WO2014087520A1 - Device for cooling hot-rolled steel sheet - Google Patents

Device for cooling hot-rolled steel sheet Download PDF

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Publication number
WO2014087520A1
WO2014087520A1 PCT/JP2012/081659 JP2012081659W WO2014087520A1 WO 2014087520 A1 WO2014087520 A1 WO 2014087520A1 JP 2012081659 W JP2012081659 W JP 2012081659W WO 2014087520 A1 WO2014087520 A1 WO 2014087520A1
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WO
WIPO (PCT)
Prior art keywords
hot
rolled steel
steel sheet
cooling
temperature
Prior art date
Application number
PCT/JP2012/081659
Other languages
French (fr)
Japanese (ja)
Inventor
透 明石
進吾 栗山
健郎 伊藤
野口　浩嗣
Original Assignee
新日鐵住金株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 新日鐵住金株式会社 filed Critical 新日鐵住金株式会社
Priority to CN201280007157.6A priority Critical patent/CN103987469B/en
Priority to PCT/JP2012/081659 priority patent/WO2014087520A1/en
Priority to BR112013028746-2A priority patent/BR112013028746B1/en
Priority to KR1020137020185A priority patent/KR101498843B1/en
Priority to US14/112,505 priority patent/US9566625B2/en
Priority to EP12873885.3A priority patent/EP2929949B1/en
Priority to JP2013512286A priority patent/JP5310966B1/en
Publication of WO2014087520A1 publication Critical patent/WO2014087520A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
    • B21B1/22—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length
    • B21B1/24—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length in a continuous or semi-continuous process
    • B21B1/26—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length in a continuous or semi-continuous process by hot-rolling, e.g. Steckel hot mill
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B37/00—Control devices or methods specially adapted for metal-rolling mills or the work produced thereby
    • B21B37/74—Temperature control, e.g. by cooling or heating the rolls or the product
    • B21B37/76—Cooling control on the run-out table
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B2273/00—Path parameters
    • B21B2273/02—Vertical deviation, e.g. slack, looper height
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B38/00—Methods or devices for measuring, detecting or monitoring specially adapted for metal-rolling mills, e.g. position detection, inspection of the product
    • B21B38/006—Methods or devices for measuring, detecting or monitoring specially adapted for metal-rolling mills, e.g. position detection, inspection of the product for measuring temperature
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B38/00—Methods or devices for measuring, detecting or monitoring specially adapted for metal-rolling mills, e.g. position detection, inspection of the product
    • B21B38/02—Methods or devices for measuring, detecting or monitoring specially adapted for metal-rolling mills, e.g. position detection, inspection of the product for measuring flatness or profile of strips

Definitions

  • the present invention relates to a hot-rolled steel sheet cooling device for cooling hot-rolled steel sheets hot-rolled by a finish rolling mill.
  • FIG. 18 is a diagram schematically showing a conventional method for producing a hot-rolled steel sheet.
  • a slab S obtained by continuously casting molten steel adjusted to a predetermined composition is rolled by a roughing mill 201, and further finished by a plurality of rolling stands 202a to 202d.
  • Hot-rolled steel sheet H having a predetermined thickness is formed by hot rolling with a rolling mill 203.
  • this hot-rolled steel sheet H is cooled by the cooling water poured from the cooling device 211, it is wound up by the winding device 212 in a coil shape.
  • the cooling device 211 is a facility for performing so-called laminar cooling on the hot-rolled steel sheet H that is generally transported from the finishing mill 203.
  • the cooling device 211 injects cooling water as jet water from above in the vertical direction to the upper surface of the hot-rolled steel sheet H moving on the run-out table, and also against the lower surface of the hot-rolled steel sheet H. Then, the hot-rolled steel sheet H is cooled by injecting cooling water as jet water through the pipe laminator.
  • Patent Document 1 discloses a technique for preventing a shape defect of a steel plate by reducing a difference in surface temperature between the upper and lower surfaces of the thick steel plate. According to the technique disclosed in Patent Document 1, based on the surface temperature difference obtained by simultaneously measuring the surface temperature of the upper and lower surfaces of the steel sheet with a thermometer during cooling by the cooling device, the upper and lower surfaces of the steel sheet Adjust the ratio of the amount of cooling water supplied to the.
  • Patent Document 2 the material to be rolled is cooled by using spray spray between two adjacent stands of the finish rolling mill to start and complete the ⁇ - ⁇ transformation of the material to be rolled.
  • a technique for preventing deterioration of the sheet-passability between the two is disclosed.
  • the steepness meter installed on the exit side of the rolling mill is used to measure the steepness at the tip of the steel sheet, and the cooling water flow rate is changed in the width direction according to the measured steepness.
  • Patent Document 4 aims at eliminating the wavy plate thickness distribution in the plate width direction of the hot-rolled steel plate and uniforming the plate thickness in the plate width direction, and in the plate width direction of the hot-rolled steel plate.
  • a technique for controlling the difference between the maximum heat transfer coefficient and the minimum heat transfer coefficient to fall within a predetermined value range is disclosed.
  • the hot-rolled steel sheet H manufactured by the manufacturing method shown in FIG. 18 is, for example, as shown in FIG. 19, a transport roll of a run-out table (hereinafter sometimes referred to as “ROT”) in the cooling device 211.
  • ROT run-out table
  • a wave shape may be generated in the rolling direction (the arrow direction in FIG. 19). In that case, variation occurs in cooling of the upper surface and the lower surface of the hot-rolled steel sheet H. That is, there is a problem that uniform cooling cannot be performed in the rolling direction due to a cooling deviation caused by the wave shape of the hot-rolled steel sheet H itself.
  • Patent Document 5 in a steel plate having a corrugated shape in the rolling direction, in order to uniformize the cooling of the steel plate, the influence of the distance between the upper landing water of the steel plate and the lower table roller is described.
  • a technique for making the cooling capacity of the upper cooling and the lower cooling the same so as to minimize is disclosed.
  • Japanese Unexamined Patent Publication No. 2005-74463 Japanese Laid-Open Patent Publication No. 5-337505 Japanese Patent Application Laid-Open No. 2005-271052 Japanese Unexamined Patent Publication No. 2003-48003 Japanese Unexamined Patent Publication No. 6-328117
  • the cooling method of Patent Document 1 does not consider the case where the hot-rolled steel sheet has a wave shape in the rolling direction.
  • the hot-rolled steel sheet H having the above-described corrugated shape as shown in FIG.
  • the hot-rolled steel sheet H is also in local contact with an apron (not shown in FIG. 19) provided as a support for preventing the hot-rolled steel sheet H from falling between the conveying rolls 220 at the corrugated bottom.
  • an apron (not shown in FIG. 19) provided as a support for preventing the hot-rolled steel sheet H from falling between the conveying rolls 220 at the corrugated bottom.
  • the corrugated hot-rolled steel sheet H a portion that is locally in contact with the transport roll 220 and the apron is more easily cooled than other portions by contact heat removal. For this reason, there existed a problem that the hot-rolled steel plate H was cooled unevenly.
  • Patent Document 1 considers that the hot-rolled steel sheet is corrugated so that the transport roll or apron and the hot-rolled steel sheet are in local contact, and the contact portion is easily cooled by contact heat removal. Absent. Therefore, there are cases where the hot-rolled steel sheet having the corrugated shape cannot be cooled uniformly.
  • Patent Document 2 the technique described in Patent Document 2 is to perform a ⁇ - ⁇ transformation between relatively low hardness (soft) ultra-low carbon steel between the stands of a finish rolling mill, and to achieve uniform cooling. It is not a thing. Further, the invention of Patent Document 2 does not relate to cooling when the material to be rolled has a wave shape in the pressure direction or when the material to be rolled is a steel material called so-called high tensile steel having a tensile strength (TS) of 800 MPa or more. Therefore, when the material to be rolled is a hot-rolled steel plate having a corrugated shape or a steel material having a relatively high hardness, there is a possibility that uniform cooling may not be performed.
  • TS tensile strength
  • Patent Document 3 the steepness in the width direction of the steel sheet is measured, and the cooling water flow rate of the portion having the high steepness is adjusted. However, if the cooling water flow rate in the plate width direction of the steel plate is changed, it becomes difficult to make the temperature in the plate width direction of the steel plate uniform. Furthermore, Patent Document 3 does not consider the case where the hot-rolled steel sheet has a wave shape in the rolling direction, and as described above, the hot-rolled steel sheet may not be uniformly cooled.
  • Patent Document 4 since the cooling of patent document 4 is the cooling of the hot-rolled steel sheet immediately before the finish rolling mill roll bite, it cannot be applied to the hot-rolled steel sheet having a predetermined thickness after finish rolling. Furthermore, Patent Document 4 does not consider the case where a wave shape is formed in the rolling direction of the hot-rolled steel sheet, and as described above, the hot-rolled steel sheet cannot be uniformly cooled in the rolling direction. There is a case.
  • the cooling capacity of the upper cooling includes the cooling by the riding water on the upper part of the steel sheet in addition to the cooling by the cooling water supplied to the steel sheet from the upper water injection nozzle. Since this boarding water is influenced by the steepness of the wave shape formed on the steel plate and the plate passing speed of the steel plate, the cooling ability of the steel plate by the boarding water cannot be specified strictly. Then, it is difficult to accurately control the cooling capacity of the upper cooling. For this reason, it is difficult to make the cooling capacity of the upper cooling and the lower cooling the same. Moreover, when the cooling capacity of the upper cooling and the lower cooling is made the same, an example of a method for determining the cooling capacity is illustrated, but a universal determination method is not disclosed. Therefore, the cooling method of patent document 5 may not cool a hot-rolled steel plate uniformly.
  • the present invention has been made in view of the above-described problems, and an object thereof is to uniformly cool a hot-rolled steel sheet that has been hot-rolled by a finish rolling mill.
  • a hot-rolled steel sheet cooling device is a hot-rolled steel sheet cooling device that cools a hot-rolled steel sheet hot-rolled by a finish rolling mill in a cooling section provided on the passage plate path.
  • a fluctuation rate calculation unit that calculates a fluctuation rate of the hot-rolled steel sheet on the downstream side of the cooling section based on the shape measurement result; and when the upward direction in the vertical direction of the hot-rolled steel sheet is positive, When the temperature of the hot-rolled steel sheet is lower than the average temperature in the range of one cycle or more of the wave shape of the hot-rolled steel sheet in a region where the fluctuation speed is positive, the lower surface cooling heat removal amount and the lower surface are reduced.
  • the temperature of the hot-rolled steel sheet is determined to be at least one of the directions in which the amount of cooling heat removal increases as the control direction and the temperature of the hot-rolled steel sheet is higher than the average temperature, the direction in which the upper surface cooling heat removal amount increases and the lower surface cooling heat removal Is determined as the control direction, and when the temperature of the hot-rolled steel sheet is lower than the average temperature in a region where the fluctuation speed is negative, the amount of heat removal from the upper surface is increased.
  • At least one of the directions in which the lower surface cooling heat removal amount decreases as the control direction, and when the temperature of the hot-rolled steel sheet is higher than the average temperature, the upper surface cooling heat removal amount decreases and the lower surface A control direction determining unit that determines at least one of the directions in which the amount of heat removal from cooling increases as the control direction; and based on the control direction determined by the control direction determining unit, the hot rolled steel sheet in the cooling section
  • a cooling heat removal amount total value adjustment unit for adjusting a total value of the upper surface cooling heat removal amount and the lower surface cooling heat removal amount.
  • a positional deviation between the temperature measurement part of the thermometer and the shape measurement part of the shape meter on the hot-rolled steel sheet is within 50 mm. .
  • the sheet-passing speed of the hot-rolled steel sheet in the cooling section is within a range of 550 m / min or more to a mechanical limit speed or less. It is preferable that it is set.
  • the hot-rolled steel sheet preferably has a tensile strength of 800 MPa or more.
  • the finish rolling mill is composed of a plurality of rolling stands, and auxiliary cooling of the hot-rolled steel sheets is performed between the rolling stands adjacent to each other. It is preferable to further include an auxiliary cooling device for performing.
  • the upper cooling capacity and the lower cooling capacity can be adjusted by detecting the phase of the temperature of the hot-rolled steel sheet and comparing it with the wave shape of the hot-rolled steel sheet.
  • the upper surface cooling heat removal amount and the lower surface cooling heat removal amount of the steel sheet can be adjusted. Therefore, after that, the hot-rolled steel sheet can be uniformly cooled by cooling the hot-rolled steel sheet with the adjusted cooling capacity.
  • the temperature of the hot-rolled steel sheet H is lower than the average temperature of the hot-rolled steel sheet H when the fluctuation speed H degree of the hot-rolled steel sheet is positive, and the temperature of the hot-rolled steel sheet H is higher when the fluctuation speed is negative.
  • the steepness of the wave shape of the hot-rolled steel sheet H is a value obtained by dividing the amplitude of the wave shape by the length in the rolling direction for one cycle.
  • the temperature of the hot-rolled steel sheet H is lower than the average temperature of the hot-rolled steel sheet H when the fluctuation speed of the hot-rolled steel sheet H is positive, and the temperature of the hot-rolled steel sheet H is higher when the fluctuation speed is negative.
  • FIG. 6 is a graph showing the relationship between the temperature fluctuation and steepness of the hot-rolled steel sheet H when the upper surface cooling heat removal amount is increased and the lower surface cooling heat removal amount is decreased. It is explanatory drawing which shows arrangement
  • FIG. It is explanatory drawing which shows the modification of the cooling device 14 in the hot rolling equipment 1.
  • FIG. It is a graph which shows the relationship between the steepness of a hot-rolled steel sheet H, and a temperature standard deviation. It is a graph which shows the relationship between the plate-feeding speed of a hot-rolled steel plate H, and a temperature standard deviation. It is explanatory drawing which shows a mode that the temperature standard deviation was formed in the plate width direction of the hot-rolled steel plate H.
  • FIG. It is explanatory drawing which shows a mode that the lowest point of the hot-rolled steel plate H contacts the conveyance roll 132.
  • FIG. It is explanatory drawing which shows a mode that the lowest point of the hot-rolled steel plate H contacts with the conveyance roll 132 and the apron 133.
  • FIG. It is a graph which shows the time-dependent change of the temperature of the hot-rolled steel sheet H when the plate-feeding speed of the hot-rolled steel sheet H is low.
  • It is explanatory drawing of the finishing mill 113 which can perform cooling between stands. It is explanatory drawing which shows the manufacturing method of the conventional hot-rolled steel plate H. It is explanatory drawing which shows the cooling method of the conventional hot-rolled steel plate H.
  • FIG. 1 schematically shows an example of a hot rolling facility 1 equipped with a hot-rolled steel sheet cooling device in the present embodiment.
  • This hot rolling facility 1 is a facility intended to continuously roll a heated slab S sandwiched between rolls up and down, thin it to a minimum of 1 mm, and wind it up.
  • This hot rolling equipment 1 is rolled in the width direction, a heating furnace 11 for heating the slab S, a width-direction rolling mill 16 that rolls the slab S heated in the heating furnace 11 in the width direction, and the width direction.
  • a roughing mill 12 that rolls the slab S from the upper and lower directions to form a rough bar, a finishing mill 13 that continuously hot-rolls the rough bar to a predetermined thickness, and a hot rolling by the finishing mill 13.
  • a cooling device 14 that cools the hot-rolled steel plate H that has been finish-rolled with cooling water, and a winding device 15 that winds the hot-rolled steel plate H cooled by the cooling device 14 into a coil shape are provided.
  • the heating furnace 11 is provided with a side burner, an axial flow burner, and a roof burner for heating the slab S by blowing out flames to the slab S carried in from the outside through the loading port.
  • the slab S carried into the heating furnace 11 is sequentially heated in each heating zone formed in each zone, and further in the soaking zone formed in the final zone, the slab S is evenly heated using a roof burner, A coercive heat treatment is performed to enable conveyance at the optimum temperature.
  • the slab S is transferred to the outside of the heating furnace 11 and moves to a rolling process by the roughing mill 12.
  • the rough rolling mill 12 allows the slab S that has been conveyed to pass through a gap between cylindrical rotary rolls that are disposed across a plurality of stands. For example, this roughing mill 12 hot-rolls the slab S only by the work rolls 12a arranged up and down in the first stand to form a rough bar.
  • the rough bar that has passed through the work roll 12a is further continuously rolled by a plurality of quadruple rolling mills 12b constituted by the work roll and the backup roll. As a result, at the end of the rough rolling step, the rough bar is rolled to a thickness of about 30 to 60 mm and conveyed to the finishing mill 13.
  • the finish rolling mill 13 finish-rolls the coarse bar conveyed from the rough rolling mill 12 until the thickness becomes about several mm. These finish rolling mills 13 allow the coarse bar to pass through the gaps between the finish rolling rolls 13a arranged in a straight line over 6 to 7 stands, and gradually reduce them.
  • the hot-rolled steel sheet H finish-rolled by the finish rolling mill 13 is conveyed to the cooling device 14 by a conveyance roll 32 described later.
  • the cooling device 14 is equipment for applying so-called laminar cooling to the hot-rolled steel sheet H conveyed from the finish rolling mill 13. As shown in FIG. 2, the cooling device 14 has an upper cooling device 14 a that jets cooling water from the upper cooling port 31 to the upper surface of the hot-rolled steel sheet H that moves on the transport roll 32 of the run-out table, The lower side cooling device 14b which injects a cooling water from the lower side cooling port 31 with respect to the lower surface of the hot-rolled steel plate H is provided. A plurality of cooling ports 31 are provided for each of the upper cooling device 14a and the lower cooling device 14b. A cooling header (not shown) is connected to the cooling port 31.
  • the cooling capacity of the upper cooling device 14a and the lower cooling device 14b is determined by the number of the cooling ports 31.
  • the cooling device 14 may be composed of at least one of an upper / lower split laminar, a pipe laminar, spray cooling, and the like. Further, a section in which the hot-rolled steel sheet H is cooled by the cooling device 14 corresponds to a cooling section in the present invention.
  • thermometer 40 that measures the temperature at a measurement position determined in the rolling direction of the hot-rolled steel sheet H
  • a shape meter 41 for measuring the wave shape of the hot-rolled steel sheet H at the same measurement position is arranged on the downstream side of the cooling section (that is, the cooling device 14).
  • the thermometer 40 and the shape meter 41 are electrically connected to the control device 50 via a cable or the like.
  • the control device 50 is electrically connected to the upper cooling device 14a and the lower cooling device 14b via a cable or the like.
  • the thermometer 40 outputs the temperature measurement result of the hot-rolled steel sheet H to the control device 50.
  • the shape meter 41 outputs the shape measurement result of the hot-rolled steel sheet H to the control device 50.
  • the control device 50 controls the upper cooling device 14a and the lower cooling device 14b on the basis of the temperature measurement result obtained from the thermometer 40 and the shape measurement result obtained from the shape meter 41, thereby performing hot rolling in the cooling section. At least one of the upper surface cooling heat removal amount and the lower surface cooling heat removal amount of the steel sheet H is controlled.
  • the control device 50 includes an average temperature calculation unit 51, a fluctuation speed calculation unit 52, a control direction determination unit 53, and a cooling heat removal total value adjustment unit 54 as functions realized by executing the program. The role of each functional unit will be described later.
  • the winding device 15 winds the hot rolled steel sheet H cooled by the cooling device 14 at a predetermined winding temperature.
  • the hot-rolled steel sheet H wound up in a coil shape by the winding device 15 is conveyed outside the hot rolling facility 1.
  • the upper cooling device 14a, the lower cooling device 14b, the thermometer 40, the shape meter 41, and the control device 50 are the hot-rolled steel sheet cooling device in the present embodiment. It is composed.
  • the cooling capacity (upper cooling capacity) of the upper cooling device 14a of the cooling apparatus 14 and the cooling capacity (lower cooling capacity) of the lower cooling device 14b are previously set. adjust.
  • the upper cooling capacity and the lower cooling capacity are respectively the heat transfer coefficient of the upper surface of the hot rolled steel sheet H cooled by the upper cooling device 14a and the heat transfer of the lower surface of the hot rolled steel sheet H cooled by the lower cooling device 14b. Adjust using the coefficient.
  • the temperature difference is a difference between the temperature of the hot-rolled steel sheet H measured by the thermometer on the inlet side of the cooling device 14 and the temperature of the cooling water used in the cooling device 14.
  • the amount of heat removed from cooling is the amount of heat removed from the hot-rolled steel sheet H in the cooling device 14, and the difference in temperature between the hot-rolled steel plates H measured by the thermometer on the inlet side and the thermometer on the outlet side of the cooling device 14. And the specific heat of the hot-rolled steel sheet H and the mass of the hot-rolled steel sheet H cooled by the cooling device 14, respectively.
  • the heat transfer coefficient of the hot-rolled steel sheet H calculated as described above is divided into the heat transfer coefficients of the upper surface and the lower surface of the hot-rolled steel sheet H.
  • These heat transfer coefficients of the upper surface and the lower surface are calculated using, for example, a ratio obtained in advance as follows. That is, the heat transfer coefficient of the hot-rolled steel sheet H when the hot-rolled steel sheet H is cooled only by the upper cooling device 14a and the heat transfer of the hot-rolled steel plate H when the hot-rolled steel plate H is cooled only by the lower cooling device 14b. Measure the coefficient. At this time, the cooling water amount from the upper cooling device 14a and the cooling water amount from the lower cooling device 14b are the same.
  • the reciprocal of the ratio of the measured heat transfer coefficient when using the upper cooling device 14a and the heat transfer coefficient when using the lower cooling device 14b is the upper side when the upper and lower heat transfer coefficient ratio is “1”. This is the vertical ratio between the amount of cooling water from the cooling device 14a and the amount of cooling water from the lower cooling device 14b. Then, the above-described heat ratio is obtained by multiplying the vertical ratio of the cooling water amount thus obtained by the cooling water amount from the upper cooling device 14a when cooling the hot-rolled steel sheet H or the cooling water amount from the lower cooling device 14b. The ratio of the heat transfer coefficient between the upper surface and the lower surface of the rolled steel sheet H is calculated.
  • the heat transfer coefficient of the hot-rolled steel sheet H that is cooled only by the upper cooling device 14a and the lower cooling device 14b is used. However, it is cooled by both the upper cooling device 14a and the lower cooling device 14b.
  • the heat transfer coefficient of the hot-rolled steel sheet H may be used. That is, the heat transfer coefficient of the hot-rolled steel sheet H when the amount of cooling water of the upper cooling device 14a and the lower cooling device 14b is changed is measured, and the ratio of the heat transfer coefficient is used to determine the upper and lower surfaces of the hot-rolled steel sheet H. The ratio of the heat transfer coefficient may be calculated.
  • the heat transfer coefficient of the hot-rolled steel sheet H is calculated, and the upper surface of the hot-rolled steel sheet H is calculated based on the above ratio (upper and lower heat transfer coefficient ratio) of the heat transfer coefficients of the upper and lower surfaces of the hot-rolled steel sheet H.
  • the heat transfer coefficient of the lower surface is calculated.
  • the cooling capacity of the upper cooling device 14a and the lower cooling device 14b is adjusted (the upper surface cooling heat removal amount and the lower surface cooling heat removal amount of the hot rolled steel plate H are controlled.
  • the inventors of the present application have made intensive studies on the characteristics of the temperature standard deviation generated by cooling in the state where the wave shape of the hot-rolled steel sheet H is generated, and as a result, have clarified the following.
  • Temperature measurement at a measurement position (hereinafter, this measurement position may be referred to as a fixed point) determined in the rolling direction of the hot-rolled steel sheet H by the thermometer 40 and the shape meter 41 with respect to the hot-rolled steel sheet H in the plate.
  • the shape measurement is performed at a constant time interval (sampling interval), and the temperature measurement result and the time series data of the shape measurement result are acquired.
  • the temperature measurement region by the thermometer 40 includes the entire width direction of the hot-rolled steel sheet H.
  • the shape refers to the height or fluctuation component of the wave pitch by using the amount of movement in the sheet passing direction of the hot-rolled steel sheet H as the amount of fluctuation in the height direction of the hot-rolled steel sheet H observed by fixed point measurement.
  • the shape measurement region includes the entire region in the width direction of the hot-rolled steel sheet H, similarly to the temperature measurement region. Moreover, when the sampling time of each measurement result is multiplied by the sheet feeding speed (conveying speed) of the hot-rolled steel sheet H, the position in the rolling direction of the hot-rolled steel sheet H from which each measurement result is obtained can be calculated. That is, when the time at which the time series data of each measurement result is sampled is multiplied by the sheet feeding speed, the time series data of each measurement result can be linked to the position in the rolling direction.
  • the total value of the upper surface cooling heat removal amount and the lower surface cooling heat removal amount of the hot-rolled steel sheet H is adjusted. Specifically, the total value of the upper surface cooling heat removal amount and the lower surface cooling heat removal amount of the hot-rolled steel sheet H is adjusted so that the time-series average value of the temperature measured by the thermometer 40 matches a predetermined target value. . And when adjusting the total value of the upper surface cooling heat removal amount and the lower surface cooling heat removal amount, for example, with respect to the theoretical value obtained in advance using an experimental theoretical formula typified by Mitsuka's formula, On / off control of the cooling header connected to the cooling device 14 may be performed based on a learning value set so as to correct the error. Alternatively, on / off of the cooling header may be feedback-controlled or feed-forward controlled based on the temperature actually measured by the thermometer 40.
  • FIG. 4 shows the relationship between the temperature fluctuation and steepness of the hot-rolled steel sheet H that is cooled in the ROT of a typical strip in a normal operation.
  • the upper and lower heat transfer coefficient ratio of the hot-rolled steel sheet H in FIG. 4 is 1.2: 1, and the upper cooling capacity is higher than the lower cooling capacity.
  • the upper graph in FIG. 4 shows the temperature variation with respect to the distance from the coil tip or the fixed point elapsed time
  • the lower graph in FIG. 4 shows the distance from the coil tip or the steepness with respect to the fixed point elapsed time.
  • a region A in FIG. 4 is a region before the strip front end portion shown in FIG.
  • a region B in FIG. 4 is a region after the strip tip portion is bitten by the coiler (a region where the wave shape is changed flat due to the influence of the unit tension). It is desired to improve a large temperature fluctuation (that is, temperature standard deviation) generated in a region where the shape of the hot-rolled steel sheet H is not flat.
  • the inventors of the present application have conducted intensive experiments with the goal of suppressing an increase in temperature standard deviation in the ROT, and as a result, have obtained the following knowledge.
  • FIG. 5 shows the temperature fluctuation component with respect to the same shape steepness of cooling in the ROT of a typical strip in a normal operation as in FIG.
  • This temperature fluctuation component is a residual obtained by subtracting a time-series average of temperature (hereinafter sometimes referred to as “average temperature”) from the actual steel plate temperature.
  • the average temperature may be averaged over a range of one or more wave shapes of the hot-rolled steel sheet H.
  • the average temperature is in principle the average of the range in units of cycles.
  • it has been confirmed by the operation data that the average temperature in the range of one cycle is not significantly different from the average temperature in the range of two cycles or more. Therefore, it is only necessary to calculate an average temperature in a range of at least one waveform.
  • the upper limit of the corrugated range of the hot-rolled steel sheet H is not particularly limited, but preferably an average temperature with sufficient accuracy can be obtained if it is set to 5 cycles. Further, even if the range to be averaged is not a cycle unit range, an acceptable average temperature can be obtained if it is in the range of 2 to 5 cycles.
  • the wave shape of the hot-rolled steel sheet H is a region where the fluctuation rate measured at a fixed point is positive.
  • the temperature of the hot-rolled steel sheet H temperature measured at a fixed point
  • the temperature of the hot-rolled steel sheet H is lower than the average temperature in the range of one cycle or more, at least one of the direction in which the upper surface cooling heat removal amount decreases and the direction in which the lower surface cooling heat removal amount increases.
  • the control direction Is determined as the control direction, and when the temperature of the hot-rolled steel sheet H is higher than the average temperature, at least one of the direction in which the upper surface cooling heat removal amount increases and the direction in which the lower surface cooling heat removal amount decreases is determined as the control direction. To do. Further, when the temperature of the hot-rolled steel sheet H is lower than the above average temperature in the region where the fluctuation rate measured at a fixed point is negative, the direction in which the upper surface cooling heat removal amount increases and the direction in which the lower surface cooling heat removal amount decreases.
  • the direction in which the upper surface cooling heat removal amount decreases and the direction in which the lower surface cooling heat removal amount increases. Is determined as a control direction, and when the temperature of the hot-rolled steel sheet H is higher than the above average temperature, at least one of the direction in which the upper surface cooling heat removal amount increases and the direction in which the lower surface cooling heat removal amount decreases is controlled. Determine as direction. Then, when at least one of the upper surface cooling heat removal amount and the lower surface cooling heat removal amount of the hot-rolled steel sheet H in the cooling section is adjusted based on the control direction determined as described above, as shown in FIG. And it turned out that the temperature fluctuation which generate
  • the hot-rolled steel sheet cooling device of the present embodiment realizes the cooling method described above. That is, the average temperature calculation unit 51 of the control device 50 calculates the time series average value of the temperature measurement results obtained from the thermometer 40 in time series as the average temperature. Further, the fluctuation speed calculation unit 52 calculates the fluctuation speed of the hot-rolled steel sheet H based on the shape measurement results obtained from the shape meter 41 in time series. If the upward direction in the vertical direction of the hot-rolled steel sheet H is positive, the control direction determining unit 53 is an area where the fluctuation rate measured at a fixed point is positive, and the average temperature in the range of one or more wave shapes of the hot-rolled steel sheet H is obtained.
  • the control direction determination unit 53 is a region where the fluctuation rate measured at a fixed point is negative, and when the temperature of the hot-rolled steel sheet H is lower than the above average temperature, the upper surface cooling heat removal amount increases and the lower surface.
  • the cooling heat removal amount total value adjustment part 54 adjusts the total value of the upper surface cooling heat removal amount and the lower surface cooling heat removal amount of the hot-rolled steel sheet H in a cooling area based on the control direction determined as mentioned above.
  • the cooling header connected to the cooling port 31 of the upper cooling device 14a and the cooling port 31 of the lower cooling device 14b When adjusting the cooling capacity of the upper cooling device 14a and the cooling capacity of the lower cooling device 14b, for example, the cooling header connected to the cooling port 31 of the upper cooling device 14a and the cooling port 31 of the lower cooling device 14b.
  • Each of the cooling headers connected to may be controlled on and off. Or you may control the cooling capacity of each cooling header in the upper side cooling device 14a and the lower side cooling device 14b. That is, you may adjust at least one of the water quantity density of the cooling water injected from each cooling port 31, a pressure, and water temperature.
  • the cooling headers (cooling ports 31) of the upper cooling device 14a and the lower cooling device 14b may be thinned out to adjust the flow rate and pressure of the cooling water injected from the upper cooling device 14a and the lower cooling device 14b.
  • the cooling capacity of the upper cooling device 14a before thinning out the cooling header is higher than the cooling capacity of the lower cooling device 14b, it is preferable to thin out the cooling header constituting the upper cooling device 14a.
  • the cooling capacity thus adjusted is used to inject cooling water onto the upper surface of the hot-rolled steel sheet H from the upper cooling device 14a, and to inject cooling water onto the lower surface of the hot-rolled steel plate H from the lower cooling device 14b.
  • the steel plate H is uniformly cooled.
  • the hot-rolled steel sheet H cooled by the cooling device 14 is subjected to fixed point measurement at the same point by the thermometer 40 and the shape meter 41, and measured as time series data.
  • the temperature measurement region includes the entire region in the width direction of the hot-rolled steel sheet H.
  • the shape indicates the amount of fluctuation in the height direction of the hot-rolled steel sheet H observed by fixed point measurement.
  • the shape measurement region includes the entire region in the width direction of the hot-rolled steel sheet H, similarly to the temperature measurement region.
  • the fluctuation rate at the fixed point of the hot-rolled steel sheet H is a positive region, and the fixed temperature of the hot-rolled steel sheet H with respect to the average temperature at the fixed point.
  • the temperature standard deviation can be reduced by decreasing the upper cooling capacity (upper surface cooling heat removal amount).
  • the temperature standard deviation can be reduced by increasing the lower cooling capacity (lower surface cooling heat removal amount). If this relationship is utilized, in order to reduce the temperature standard deviation, it becomes clear which of the upper cooling device 14a and the lower cooling device 14b of the cooling device 14 should be adjusted.
  • the increase / decrease direction (control direction) of the upper cooling capacity (upper surface cooling heat removal amount) and lower cooling capacity (lower surface cooling heat removal amount) to reduce the temperature standard deviation is determined, and the vertical heat transfer coefficient ratio is adjusted. Can do. Further, based on the magnitude of the temperature standard deviation, the upper and lower heat transfer coefficient ratio can be determined so that the temperature standard deviation falls within an allowable range, for example, a range from the minimum value to the minimum value + 10 ° C.
  • the temperature standard deviation is within the range from the minimum value to the minimum value + 10 ° C.
  • variations in yield stress, tensile strength, and the like can be suppressed within manufacturing tolerances, and the hot-rolled steel sheet H can be cooled uniformly.
  • the cooling water volume density ratio is within ⁇ 5% of the cooling water volume density ratio at which the temperature standard deviation is the minimum value
  • the temperature standard deviation is within the minimum value + 10 ° C from the minimum value.
  • the vertical ratio of the cooling water amount density (cooling water amount density ratio) within ⁇ 5% with respect to the cooling water amount density ratio at which the temperature standard deviation is the minimum value.
  • this allowable range does not necessarily include the same upper and lower water density.
  • the temperature and wave shape of the further cooled hot-rolled steel sheet H are changed. Based on the measurement result, the cooling capacity of the upper cooling device 14a and the cooling capacity of the lower cooling device 14b are adjusted. In this way, the cooling capacity of the upper cooling device 14a and the lower cooling device 14b can be feedback-controlled to adjust the cooling capacity to an appropriate cooling capacity qualitatively and quantitatively, so that the uniformity of the hot-rolled steel sheet H that is subsequently cooled is further improved. Can be made.
  • the hot-rolled steel sheet H can be uniformly cooled with the temperature standard deviation of the hot-rolled steel sheet H being minimized.
  • the temperature and shape of the hot-rolled steel sheet H were measured at the same measurement position by the thermometer 40 and the shape meter 41.
  • the thermometer 40 and the shape meter were measured. It has been found that the measurement positions of 41 need not be exactly the same. Specifically, as shown in FIG. 8, the displacement (distance) L between the temperature measurement point P1 of the thermometer 40 and the shape measurement point P2 of the shape meter 41 on the hot-rolled steel sheet H is more preferably within 50 mm. It was found that the temperature and shape of the hot-rolled steel sheet H can be properly grasped within 30 mm.
  • the direction of the positional deviation L between the measurement points of the thermometer 40 and the shape meter 41 may be the sheet passing direction of the hot-rolled steel sheet H as shown in FIG. It may be any direction.
  • the thermometer 40 is disposed on the upstream side of the shape meter 41, but conversely, the shape meter 41 may be disposed on the upstream side of the thermometer 40.
  • Table 2 shows the positional deviation L between the measurement points of the thermometer 40 and the shape meter 41 under the conditions of the same vertical heat transfer coefficient ratio, steepness, and plate passing speed when the present invention is applied to an actual machine.
  • the temperature standard deviation of the hot-rolled steel sheet H and the difference between each temperature standard deviation and the minimum value (minimum value 10.0 in Table 2) when changed in the range of ⁇ 200 to +200 mm with respect to the rolling direction. It shows the relationship with (difference of standard deviation from minimum value).
  • the positional deviation L when the shape measurement point P2 of the shape meter 41 is set on the downstream side is shown as a positive value.
  • the position deviation L when the shape measuring point P2 of the shape meter 41 is set is indicated by a negative value.
  • the positional deviation L becomes zero.
  • the difference in the standard deviation from the minimum value can be reduced to + 10 ° C. or less as long as the positional deviation L between the measurement points of the thermometer 40 and the shape meter 41 is within 50 mm regardless of positive or negative. I understand.
  • the increase and decrease directions of the upper cooling capacity and the lower cooling capacity for reducing the temperature standard deviation are the same as in the above embodiment. (Control direction) can be determined, and feedback control of the cooling capacity of the upper cooling device 14a and the lower cooling device 14b can be performed.
  • the cooling zone in which the hot-rolled steel sheet H is cooled may be divided into a plurality of, for example, two divided cooling zones Z1 and Z2 in the rolling direction.
  • a cooling device 14 is provided in each of the divided cooling zones Z1 and Z2.
  • a thermometer 40 and a shape meter 41 are provided at the boundary between the divided cooling zones Z1 and Z2, that is, downstream of the divided cooling zones Z1 and Z2.
  • the cooling section is divided into two divided cooling sections, but the number of divisions is not limited to this and can be arbitrarily set.
  • the cooling section may be divided into 1 to 5 divided cooling sections.
  • the temperature and the wave shape of the hot-rolled steel sheet H on the downstream side of the divided cooling zones Z1 and Z2 are measured by the thermometers 40 and the shape meters 41, respectively. And based on these measurement results, the cooling capacity of the upper side cooling device 14a and the lower side cooling device 14b in each division
  • the cooling capacity of the upper cooling device 14a and the lower cooling device 14b is feedback-controlled based on the measurement results of the thermometer 40 and the shape meter 41 on the downstream side, and the upper surface cooling heat removal amount and At least one of the bottom surface cooling heat removal amount is adjusted.
  • the cooling capacity of the upper cooling device 14a and the lower cooling device 14b may be feedforward controlled based on the measurement results of the thermometer 40 and the shape meter 41 on the downstream side, Alternatively, feedback control may be performed. In any case, at least one of the upper surface cooling heat removal amount and the lower surface cooling heat removal amount is adjusted in the divided cooling zone Z2.
  • the method for controlling the cooling capacity of the upper cooling device 14a and the lower cooling device 14b based on the measurement results of the thermometer 40 and the shape meter 41 is the same as that in the above embodiment described with reference to FIGS. Therefore, detailed description is omitted.
  • the hot-rolled steel sheet H can be cooled more uniformly.
  • the measurement results of the thermometer 40 and the shape meter 41 are used.
  • at least one of the wave shape steepness of the hot-rolled steel sheet H and the sheet passing speed of the hot-rolled steel sheet H may be used. For example, since the steepness and the sheet passing speed of the hot-rolled steel sheet H may not be constant for each coil, the steepness and the sheet passing speed are also taken into consideration.
  • the change of the temperature standard deviation with respect to the ratio of the vertical heat transfer coefficient can be qualitatively evaluated but cannot be quantitatively and accurately evaluated. Therefore, for example, a temperature standard deviation corresponding to the steepness or sheet passing speed of the hot-rolled steel sheet H is obtained in advance, and at least the steepness or sheet passing speed of the hot-rolled steel sheet H is measured to correct the temperature standard deviation. And based on this correct
  • FIG. 12 shows an example of a wave shape in which different amplitudes are generated in the plate width direction due to middle elongation. As described above, even if the temperature standard deviation occurs due to the wave shapes having different amplitudes generated in the plate width direction, the temperature standard deviation in the plate width direction is reduced according to the above-described embodiment. It becomes possible.
  • the hot-rolled steel sheet H is made more uniform by setting the sheet-passing speed of the hot-rolled steel sheet H within a range from 550 m / min or more to a mechanical limit speed or less. I understood that I can do it.
  • FIG. 13 schematically shows an example of the hot rolling facility 2 in another embodiment.
  • This hot rolling facility 2 is a facility intended to continuously roll a heated slab S sandwiched between rolls and to roll it down to a minimum thickness of 1.2 mm.
  • This hot rolling facility 2 is rolled in the width direction, a heating furnace 111 for heating the slab S, a width-direction rolling mill 116 that rolls the slab S heated in the heating furnace 111 in the width direction, and the width direction.
  • a roughing mill 112 that rolls the slab S from above and below to form a rough bar, a finishing mill 113 that continuously hot-rolls the rough bar to a predetermined thickness, and a hot rolling by the finishing mill 113.
  • a cooling device 114 that cools the hot-rolled steel sheet H that has been finish-rolled with cooling water, and a winding device 115 that winds the hot-rolled steel plate H cooled by the cooling device 114 into a coil shape.
  • the heating furnace 111 is provided with a side burner, an axial flow burner, and a roof burner for heating the slab S by blowing out flames with respect to the slab S carried in from the outside through the loading port.
  • the slab S carried into the heating furnace 111 is sequentially heated in each heating zone formed in each zone, and further, in the soaking zone formed in the final zone, by heating the slab S evenly using a roof burner, A coercive heat treatment is performed to enable conveyance at the optimum temperature.
  • the slab S is transferred to the outside of the heating furnace 111 and moves to a rolling process by the rough rolling mill 112.
  • the slab S conveyed from the heating furnace 111 passes through a gap between cylindrical rotary rolls arranged over a plurality of stands.
  • the rough rolling mill 112 hot-rolls the slab S with only the work rolls 112a disposed up and down in the first stand to form a rough bar.
  • the coarse bar that has passed through the work roll 112a is further continuously rolled by a plurality of quadruple rolling mills 112b each composed of a work roll and a backup roll.
  • the rough bar is rolled to a thickness of about 30 to 60 mm and conveyed to the finishing mill 113.
  • the structure of the rough rolling mill 112 is not limited to what was described in this embodiment, The number of rolls etc. can be set arbitrarily.
  • the finish rolling mill 113 finish-rolls the rough bar conveyed from the rough rolling mill 112 until the thickness becomes about several mm. These finish rolling mills 113 allow the coarse bars to pass through the gaps between the finish rolling rolls 113a arranged in a straight line over 6 to 7 stands, and gradually reduce them.
  • the hot-rolled steel sheet H finish-rolled by the finish rolling mill 113 is transported to the cooling device 114 by a transport roll 132 (see FIG. 14).
  • the rolling mill provided with the above-described pair of finish rolling rolls 113a arranged in a straight line is also referred to as a so-called rolling stand.
  • a cooling device 142 that performs cooling between the stands (auxiliary cooling) during finish rolling is provided between the rolling rolls 113a arranged over 6 to 7 stands (that is, between the rolling stands). Has been placed.
  • FIG. 13 shows a case where the cooling devices 142 are arranged at two locations in the finishing mill 113, but this cooling device 142 may be provided between all the rolling rolls 113a. The structure provided only in a part may be sufficient.
  • the cooling device 114 is a facility for cooling the hot-rolled steel sheet H conveyed from the finish rolling mill 113 by nozzle laminator or spray. As shown in FIG. 14, the cooling device 114 has an upper cooling device 114a for injecting cooling water from the upper cooling port 131 to the upper surface of the hot-rolled steel sheet H moving on the transport roll 132 of the run-out table, On the lower surface of the hot-rolled steel sheet H, a lower cooling device 114b for injecting cooling water from the lower cooling port 131 is provided. A plurality of cooling ports 131 are provided for each of the upper cooling device 114a and the lower cooling device 114b. A cooling header (not shown) is connected to the cooling port 131.
  • the cooling capacity of the upper cooling device 114a and the lower cooling device 114b is determined by the number of the cooling ports 131.
  • the cooling device 114 may be composed of at least one of upper and lower split laminar, pipe laminar, spray cooling, and the like.
  • the cooling header connected to the cooling port 131 of the upper cooling device 114a and the lower cooling device 114b may be on / off controlled respectively. Or you may control the operation parameter of each cooling header in the upper side cooling device 114a and the lower side cooling device 114b. That is, at least one of the water density, pressure, and water temperature of the cooling water ejected from each cooling port 131 may be adjusted.
  • the cooling headers (cooling ports 131) of the upper cooling device 114a and the lower cooling device 114b may be thinned out to adjust the flow rate and pressure of the cooling water injected from the upper cooling device 114a and the lower cooling device 114b.
  • the cooling capacity of the upper cooling device 114a before thinning out the cooling header is higher than the cooling capacity of the lower cooling device 114b, it is preferable to thin out the cooling header constituting the upper cooling device 114a.
  • the winding device 115 winds the hot-rolled steel sheet H cooled by the cooling device 114 at a predetermined winding temperature.
  • the hot-rolled steel sheet H wound in a coil shape by the winding device 115 is transported outside the hot rolling facility 2.
  • the hot-rolled steel sheet H in which a corrugated shape whose surface height (wave height) fluctuates in the rolling direction is formed is performed, As described above, the hot-rolled steel sheet H is made uniform by appropriately adjusting the water density, pressure, water temperature, etc. of the cooling water injected from the upper cooling device 114a and the cooling water injected from the lower cooling device 114b. Can be cooled. However, especially when the sheet passing speed of the hot-rolled steel sheet H is slow, the time for which the hot-rolled steel sheet H and the transport roll 132 and the apron 133 are in contact with each other is long, and the transport roll 132 and apron of the hot-rolled steel sheet H are increased. Since the contact portion with 133 is easily cooled by contact heat removal, the cooling becomes uneven. The cause of this non-uniform cooling will be described below with reference to the drawings.
  • the corrugated bottom of the hot-rolled steel sheet H may locally contact the transport roll 132.
  • the apron 133 may be provided as a support for preventing that the hot-rolled steel plate H falls between the conveyance rolls 132 adjacent along a rolling direction.
  • the corrugated bottom portion of the hot-rolled steel sheet H locally contacts the transport roll 132 and the apron 133.
  • the part that locally contacts the transport roll 132 and the apron 133 is more easily cooled than the other part due to contact heat removal. For this reason, the hot-rolled steel sheet H is cooled unevenly.
  • the time during which the hot-rolled steel sheet H locally contacts the transport roll 132 and the apron 133 becomes longer.
  • the portion where the hot-rolled steel sheet H is locally in contact with the transport roll 132 and the apron 133 is more easily cooled than the other portions.
  • the rolled steel sheet H is cooled unevenly.
  • the contact time is shortened.
  • the hot rolled sheet steel H in the sheet passing plate is lifted from the sheet conveying roll 132 and the apron 133 due to repulsion due to contact between the hot rolled sheet steel H and the conveying roll 132 and the apron 133.
  • the hot-rolled steel sheet H is lifted from the transport roll 132 and the apron 133 due to the repulsion due to the contact, and the hot-rolled steel sheet H and the transport roll 132 Since the contact time and the number of times of contact with the apron 133 are reduced, the temperature drop due to the contact becomes negligibly small.
  • the hot-rolled steel sheet H can be cooled more uniformly as shown in FIG. 16B.
  • the inventors have found that the hot-rolled steel sheet H can be cooled sufficiently uniformly by setting the sheet passing speed to 550 m / min or more in addition to the above-described heat removal control on the upper and lower surfaces.
  • the lowest point of the hot-rolled steel sheet H is conveyed regardless of the height of the corrugated shape. Since it comes in contact with the roll 132 and the apron 133, increasing the sheet passing speed regardless of the height of the wave shape is effective for uniform cooling.
  • the hot-rolled steel sheet H will be in the state which floated from the conveyance roll 132 or the apron 133 if the plate-feeding speed of the hot-rolled steel sheet H is set to 550 m / min or more, cooling water is supplied to the hot-rolled steel sheet H in this state. Even if it injects, there is no boarding water on the hot-rolled steel sheet H as in the prior art. Therefore, it is possible to avoid the hot-rolled steel sheet H from being unevenly cooled due to the riding water.
  • the sheet passing speed of the hot-rolled steel sheet H in the cooling section is set to 550 m / min or more, the hot-rolled steel sheet H having a wave shape whose wave height periodically varies in the rolling direction is more uniformly cooled. it can.
  • the plate-passing speed of the hot-rolled steel sheet H is better as it is higher, it is impossible to exceed the mechanical limit speed (for example, 1550 m / min). Therefore, the sheet feeding speed of the hot-rolled steel sheet H in the cooling section is substantially set within a range from 550 m / min or more to a mechanical limit speed or less.
  • the operation upper limit speed (for example, 1200 m / min) is set from 550 m / min or more. min) is preferably set within a range up to or below.
  • the hot-rolled steel sheet cooling device described with reference to FIG. 3 is applied to the hot rolling facility 2 to control the upper surface cooling heat removal amount and the lower surface cooling heat removal amount of the hot-rolled steel sheet H, and to set a high plate feed speed. (Set within a range from 550 m / min or more to a mechanical limit speed or less) may be combined.
  • the steel sheet is a hot-rolled steel sheet H having a high tensile strength (particularly a steel sheet called so-called high tensile steel having a tensile strength (TS) of 800 MPa or more and a practical upper limit of 1400 MPa).
  • TS tensile strength
  • the sheet passing speed of the hot-rolled steel sheet H in the cooling device 114 is kept low, when the corrugated shape is formed on the hot-rolled steel sheet H, as described above, the hot-rolled steel sheet H, the transport roll 132, the apron 133, Due to the local contact, the contact portion is easily cooled by contact heat removal, and uneven cooling is performed.
  • the inventors of the present application in the finishing mill 113 of the hot rolling facility 2, for example, cooled between a pair of finish rolling rolls 113a (that is, rolling stands) provided over, for example, 6 to 7 stands (so-called rolling stands). It was found that by performing (cooling between stands), the processing heat generation can be suppressed, and the sheet feeding speed of the hot-rolled steel sheet H in the cooling device 114 can be set to 550 m / min or more.
  • the inter-stand cooling will be described with reference to FIG.
  • FIG. 17 is an explanatory diagram of the finishing mill 113 capable of performing inter-stand cooling.
  • the finish rolling mill 113 is provided with a plurality of rolling stands 140 (three in FIG. 17) including a pair of finish rolling rolls 113a and the like arranged in a straight line.
  • the cooling device 142 which is the equipment which performs nozzle cooling by a laminar or a spray is provided, and inter-stand cooling is performed with respect to the hot-rolled steel sheet H between the rolling stands 140. It is possible.
  • the cooling device 142 includes an upper cooling device 142 a that ejects cooling water from the upper side through a cooling port 146 to the hot rolled steel plate H conveyed in the finish rolling mill 113, and a lower surface of the hot rolled steel plate H. And a lower cooling device 142b for ejecting cooling water from the lower side.
  • a plurality of cooling ports 146 are provided for each of the upper cooling device 142a and the lower cooling device 142b.
  • a cooling header (not shown) is connected to the cooling port 146.
  • the cooling device 142 may be composed of at least one of upper and lower split laminar, pipe laminar, spray cooling, and the like.
  • the finish rolling mill 113 having the configuration shown in FIG. 17, particularly when the tensile strength (TS) of the hot-rolled steel sheet H is 800 MPa or more, processing heat generation of the hot-rolled steel sheet H is suppressed by performing inter-stand cooling. . Thereby, it is possible to keep the sheet passing speed of the hot-rolled steel sheet H in the cooling device 114 at 550 m / min or more. Therefore, the contact portion is easily cooled by contact heat removal due to local contact between the hot-rolled steel sheet H and the transport roll 132 or the apron 133, which has been a problem when cooling is performed at a conventional low plate speed. Therefore, the hot-rolled steel sheet H can be cooled sufficiently uniformly.
  • TS tensile strength
  • the cooling of the hot-rolled steel sheet H by the cooling device 114 is preferably performed in the range from the finish rolling mill outlet temperature to the temperature of the hot-rolled steel sheet H up to 600 ° C.
  • the temperature region where the temperature of the hot-rolled steel sheet H is 600 ° C. or higher is a so-called film boiling region. That is, in this case, the so-called transition boiling region can be avoided and the hot-rolled steel sheet H can be water-cooled in the film boiling region.
  • the transition boiling region when the cooling water is sprayed on the surface of the hot-rolled steel sheet H, the surface covered with the vapor film on the surface of the hot-rolled steel sheet H, the part where the cooling water is directly sprayed on the hot-rolled steel sheet H, Are mixed.
  • the hot-rolled steel sheet H cannot be cooled uniformly.
  • the hot-rolled steel sheet H in the film boiling region, since the hot-rolled steel sheet H is cooled in a state where the entire surface of the hot-rolled steel sheet H is covered with the vapor film, the hot-rolled steel sheet H can be uniformly cooled. Therefore, the hot-rolled steel sheet H can be cooled more uniformly in the range where the temperature of the hot-rolled steel sheet H is 600 ° C. or more as in this embodiment.
  • the present inventor conducted a cooling experiment on the hot-rolled steel sheet as an example. It was.
  • Example 1 The hot-rolled steel sheet on which a plate thickness of 2.5 mm, a width of 1200 mm, a tensile strength of 400 MPa, and a steepness of 2% was formed was cooled by changing the sheet passing speed in the cooling device. Specifically, the sheeting speed is changed to 400 m / min, 450 m / min, 500 m / min, 550 m / min, 600 m / min, and 650 m / min, and the hot-rolled steel sheet is cooled 20 times at each sheeting speed. I went one by one.
  • CT temperature fluctuation amount the average value of the standard deviation of temperature fluctuation was computed using the temperature measurement result.
  • Table 3 The results of evaluating the calculated CT temperature fluctuation amount are shown in Table 3 below. As an evaluation standard, when the CT temperature fluctuation amount is larger than 25 ° C., it is evaluated that it is not uniformly cooled, and when the CT temperature fluctuation amount is 25 ° C. or less, it is uniformly cooled. evaluated.
  • the CT temperature fluctuation amount is not sufficiently reduced (higher than 25 ° C.), and the hot-rolled steel sheet is sufficiently cooled uniformly. I have not been told.
  • the CT temperature fluctuation amount was suppressed to 25 ° C. or less, and it was found that the hot-rolled steel sheet was uniformly cooled.
  • the CT temperature is suppressed to less than 10 ° C. (8 ° C., 6 ° C.), so this condition realizes uniform cooling of the hot-rolled steel plate. It was found that this is more preferable.
  • Example 2 A hot-rolled steel sheet having a plate thickness of 2.5 mm, a width of 1200 mm, a tensile strength of 800 MPa and a steepness of 2% is cooled between stands so that the exit side temperature of finish rolling is 880 ° C. Cooling was carried out by changing the plate feeding speed. Specifically, the sheeting speed is changed to 400 m / min, 450 m / min, 500 m / min, 550 m / min, 600 m / min, and 650 m / min, and the hot-rolled steel sheet is cooled 20 times at each sheeting speed. I went one by one.
  • CT temperature fluctuation amount the average value of the standard deviation of temperature fluctuation was computed using the temperature measurement result.
  • Table 4 The results of evaluating the calculated CT temperature fluctuation amount are shown in Table 4 below. Note that the evaluation criteria are the same as in the case of Example 1, and cooling between stands is not performed only when the plate passing speed is 400 m / min.
  • the CT temperature fluctuation amount is not sufficiently reduced (higher than 25 ° C.) even when the cooling between the stands is performed, and the hot-rolled steel sheet The uniform cooling is not sufficiently performed.
  • the sheet feeding speed was 550 m / min or more, the CT temperature fluctuation amount was suppressed to 25 ° C. or less, and it was found that the hot-rolled steel sheet was uniformly cooled.
  • the CT temperature fluctuation amount is suppressed even for a hot rolled steel sheet having a relatively high hardness (tensile strength of 800 MPa). That is, in addition to setting the sheeting speed during cooling of the hot-rolled steel sheet to 550 m / min or more, it is uniform for all steel materials, particularly steel materials with high hardness, by carrying out inter-stand rolling with a finish rolling mill. It became clear that it was possible to cool.
  • the present invention is useful when cooling a hot-rolled steel sheet that has been hot-rolled by a finish rolling mill and has a corrugated shape whose surface height varies in the rolling direction.

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Abstract

This device for cooling a hot-rolled steel sheet comprises: a thermometer that measures the temperature of a hot-rolled steel sheet; a shape gauge that measures the shape of the hot-rolled steel sheet; an upper-side cooling device that cools the upper surface of the hot-rolled steel sheet in a cooling zone; a lower-side cooling device that cools the lower surface of the hot-rolled steel sheet in the cooling zone; and a control device that controls the upper-surface cooling/heat-removal amount and/or the lower-surface cooling/heat-removal amount of the hot-rolled steel sheet in the cooling zone by controlling the upper-side cooling device and the lower-side cooling device on the basis of the temperature measurement result and the shape measurement result.

Description

熱延鋼板冷却装置Hot-rolled steel sheet cooling device
　本発明は、仕上圧延機で熱間圧延された熱延鋼板を冷却する熱延鋼板冷却装置に関する。 The present invention relates to a hot-rolled steel sheet cooling device for cooling hot-rolled steel sheets hot-rolled by a finish rolling mill.
例えば自動車及び産業機械等に使用される熱延鋼板は、一般に、粗圧延工程及び仕上圧延工程を経て製造される。図１８は、従来の熱延鋼板の製造方法を模式的に示す図である。熱延鋼板の製造工程においては、先ず、所定の組成に調整した溶鋼を連続鋳造して得たスラブＳを粗圧延機２０１により圧延した後、さらに複数の圧延スタンド２０２ａ～２０２ｄで構成される仕上圧延機２０３により熱間圧延して、所定の厚さの熱延鋼板Ｈを形成する。そして、この熱延鋼板Ｈは、冷却装置２１１から注水される冷却水によって冷却された後、巻取装置２１２によりコイル状に巻き取られる。 For example, hot-rolled steel sheets used for automobiles and industrial machines are generally manufactured through a rough rolling process and a finish rolling process. FIG. 18 is a diagram schematically showing a conventional method for producing a hot-rolled steel sheet. In the production process of hot-rolled steel sheets, first, a slab S obtained by continuously casting molten steel adjusted to a predetermined composition is rolled by a roughing mill 201, and further finished by a plurality of rolling stands 202a to 202d. Hot-rolled steel sheet H having a predetermined thickness is formed by hot rolling with a rolling mill 203. And after this hot-rolled steel sheet H is cooled by the cooling water poured from the cooling device 211, it is wound up by the winding device 212 in a coil shape.
　冷却装置２１１は、一般に仕上圧延機２０３から搬送される熱延鋼板Ｈに対していわゆるラミナー冷却を施すための設備である。この冷却装置２１１は、ランナウトテーブル上を移動する熱延鋼板Ｈの上面に対して、垂直方向の上方から冷却ノズルを介して冷却水を噴流水として噴射すると共に、熱延鋼板Ｈの下面に対して、パイプラミナーを介して噴流水として冷却水を噴射することにより、熱延鋼板Ｈを冷却する。 The cooling device 211 is a facility for performing so-called laminar cooling on the hot-rolled steel sheet H that is generally transported from the finishing mill 203. The cooling device 211 injects cooling water as jet water from above in the vertical direction to the upper surface of the hot-rolled steel sheet H moving on the run-out table, and also against the lower surface of the hot-rolled steel sheet H. Then, the hot-rolled steel sheet H is cooled by injecting cooling water as jet water through the pipe laminator.
　そして、従来において、例えば特許文献１には、厚鋼板の上下面の表面温度差を低減させることにより、その鋼板の形状不良を防止する技術が開示されている。この特許文献１に開示された技術によれば、冷却装置による冷却時において鋼板の上面及び下面の表面温度を温度計で同時に測定して得られた表面温度差に基づいて、鋼板の上面と下面に供給する冷却水の水量比を調整する。 Conventionally, for example, Patent Document 1 discloses a technique for preventing a shape defect of a steel plate by reducing a difference in surface temperature between the upper and lower surfaces of the thick steel plate. According to the technique disclosed in Patent Document 1, based on the surface temperature difference obtained by simultaneously measuring the surface temperature of the upper and lower surfaces of the steel sheet with a thermometer during cooling by the cooling device, the upper and lower surfaces of the steel sheet Adjust the ratio of the amount of cooling water supplied to the.
　また、例えば特許文献２には、仕上圧延機の隣接する２つのスタンド間において噴射スプレーを用いて被圧延材の冷却を行うことで、被圧延材のγ－α変態を開始及び完了させ、スタンド間における通板性悪化を防止する技術が開示されている。 Further, for example, in Patent Document 2, the material to be rolled is cooled by using spray spray between two adjacent stands of the finish rolling mill to start and complete the γ-α transformation of the material to be rolled. A technique for preventing deterioration of the sheet-passability between the two is disclosed.
　また、例えば特許文献３には、圧延機出口側に設置した急峻度計により、鋼板先端の急峻度を測定し、その測定した急峻度に応じて冷却水流量を幅方向に変えて調整することにより、鋼板の穴あきを防止する技術が開示されている。 Also, for example, in Patent Document 3, the steepness meter installed on the exit side of the rolling mill is used to measure the steepness at the tip of the steel sheet, and the cooling water flow rate is changed in the width direction according to the measured steepness. Thus, a technique for preventing perforation of a steel sheet is disclosed.
　さらに、例えば特許文献４には、熱延鋼板の板幅方向における波形状の板厚分布を解消し、板幅方向の板厚を均一化させることを目的とし、熱延鋼板の板幅方向における最高熱伝達率と最低熱伝達率との差が所定値の範囲に収まるように制御する技術が開示されている。 Furthermore, for example, Patent Document 4 aims at eliminating the wavy plate thickness distribution in the plate width direction of the hot-rolled steel plate and uniforming the plate thickness in the plate width direction, and in the plate width direction of the hot-rolled steel plate. A technique for controlling the difference between the maximum heat transfer coefficient and the minimum heat transfer coefficient to fall within a predetermined value range is disclosed.
　ここで、図１８に示した製造方法によって製造される熱延鋼板Ｈは、例えば図１９に示すように冷却装置２１１におけるランナウトテーブル（以降、「ＲＯＴ」と記載する場合がある。）の搬送ロール２２０上で圧延方向（図１９中の矢印方向）に波形状を生ずる場合がある。その場合、熱延鋼板Ｈの上面と下面の冷却にバラツキが生じてしまう。すなわち、熱延鋼板Ｈ自身が有する波形状に起因した冷却偏差によって、圧延方向に対して均一な冷却を行うことができなくなるという問題点があった。 Here, the hot-rolled steel sheet H manufactured by the manufacturing method shown in FIG. 18 is, for example, as shown in FIG. 19, a transport roll of a run-out table (hereinafter sometimes referred to as “ROT”) in the cooling device 211. On 220, a wave shape may be generated in the rolling direction (the arrow direction in FIG. 19). In that case, variation occurs in cooling of the upper surface and the lower surface of the hot-rolled steel sheet H. That is, there is a problem that uniform cooling cannot be performed in the rolling direction due to a cooling deviation caused by the wave shape of the hot-rolled steel sheet H itself.
　そこで、例えば特許文献５には、圧延方向に波形状が形成された鋼板において、その鋼板の冷却を均一化するために、その鋼板の上部の乗り水と下部のテーブルローラーとの距離の影響を最小化するように、上部冷却と下部冷却の冷却能力を同一にする技術が開示されている。 Thus, for example, in Patent Document 5, in a steel plate having a corrugated shape in the rolling direction, in order to uniformize the cooling of the steel plate, the influence of the distance between the upper landing water of the steel plate and the lower table roller is described. A technique for making the cooling capacity of the upper cooling and the lower cooling the same so as to minimize is disclosed.
日本国特開２００５－７４４６３号公報Japanese Unexamined Patent Publication No. 2005-74463 日本国特開平５－３３７５０５号公報Japanese Laid-Open Patent Publication No. 5-337505 日本国特開２００５－２７１０５２号公報Japanese Patent Application Laid-Open No. 2005-271052 日本国特開２００３－４８００３号公報Japanese Unexamined Patent Publication No. 2003-48003 日本国特開平６－３２８１１７号公報Japanese Unexamined Patent Publication No. 6-328117
　しかしながら、特許文献１の冷却方法は、熱延鋼板が圧延方向に波形状を有する場合を考慮していない。上述した波形状を有する熱延鋼板Ｈにおいては、図１９に示すように、波形状の底部において搬送ロール２２０と局所的に接触する場合がある。また、熱延鋼板Ｈは、波形状底部において、搬送ロール２２０同士の間に熱延鋼板Ｈの落ち込みを防止するためのサポートとして設けられるエプロン（図１９には図示せず）とも局所的に接触する場合がある。波形状の熱延鋼板Ｈにおいて、搬送ロール２２０やエプロンと局所的に接触する部分は、接触抜熱によって他の部分よりも冷却され易くなる。このため、熱延鋼板Ｈが不均一に冷却されるという問題点があった。即ち、特許文献１では、熱延鋼板が波形状であることで搬送ロールやエプロンと熱延鋼板とが局所的に接触し、その接触部分が接触抜熱によって冷却され易くなることを考慮していない。したがって、このように波形状が形成された熱延鋼板を均一に冷却することができない場合がある。 However, the cooling method of Patent Document 1 does not consider the case where the hot-rolled steel sheet has a wave shape in the rolling direction. In the hot-rolled steel sheet H having the above-described corrugated shape, as shown in FIG. Further, the hot-rolled steel sheet H is also in local contact with an apron (not shown in FIG. 19) provided as a support for preventing the hot-rolled steel sheet H from falling between the conveying rolls 220 at the corrugated bottom. There is a case. In the corrugated hot-rolled steel sheet H, a portion that is locally in contact with the transport roll 220 and the apron is more easily cooled than other portions by contact heat removal. For this reason, there existed a problem that the hot-rolled steel plate H was cooled unevenly. That is, Patent Document 1 considers that the hot-rolled steel sheet is corrugated so that the transport roll or apron and the hot-rolled steel sheet are in local contact, and the contact portion is easily cooled by contact heat removal. Absent. Therefore, there are cases where the hot-rolled steel sheet having the corrugated shape cannot be cooled uniformly.
　また、特許文献２に記載の技術は、比較的硬度の低い（軟らかい）極低炭素鋼を仕上圧延機のスタンド間においてγ－α変態させるものであり、均一な冷却を行うことを目的とするものではない。また、特許文献２の発明は、被圧延材が圧方向に波形状を有する場合や、被圧延材が引張強度（ＴＳ）８００ＭＰａ以上のいわゆるハイテンと呼ばれる鋼材である場合についての冷却に関するものではないため、被圧延材が波形状を有する熱延鋼板である場合や比較的硬度の高い鋼材である場合には、均一な冷却が行われない虞がある。 In addition, the technique described in Patent Document 2 is to perform a γ-α transformation between relatively low hardness (soft) ultra-low carbon steel between the stands of a finish rolling mill, and to achieve uniform cooling. It is not a thing. Further, the invention of Patent Document 2 does not relate to cooling when the material to be rolled has a wave shape in the pressure direction or when the material to be rolled is a steel material called so-called high tensile steel having a tensile strength (TS) of 800 MPa or more. Therefore, when the material to be rolled is a hot-rolled steel plate having a corrugated shape or a steel material having a relatively high hardness, there is a possibility that uniform cooling may not be performed.
　また、特許文献３の冷却方法では、鋼板の幅方向の急峻度を測定して、その急峻度の高い部分の冷却水流量を調整している。しかしながら、鋼板の板幅方向の冷却水流量を変更すると、その鋼板の板幅方向の温度を均一にするのは困難となる。さらに、特許文献３においても、熱延鋼板が圧延方向に波形状を有する場合を考慮しておらず、上述したように熱延鋼板を均一に冷却することはできない場合がある。 Further, in the cooling method of Patent Document 3, the steepness in the width direction of the steel sheet is measured, and the cooling water flow rate of the portion having the high steepness is adjusted. However, if the cooling water flow rate in the plate width direction of the steel plate is changed, it becomes difficult to make the temperature in the plate width direction of the steel plate uniform. Furthermore, Patent Document 3 does not consider the case where the hot-rolled steel sheet has a wave shape in the rolling direction, and as described above, the hot-rolled steel sheet may not be uniformly cooled.
　また、特許文献４の冷却は、仕上圧延機ロールバイトの直前における熱延鋼板の冷却であるため、仕上圧延されて所定の厚みになった熱延鋼板に適用できない。さらに、特許文献４においても、熱延鋼板の圧延方向に波形状が形成される場合を考慮しておらず、上述したように熱延鋼板をその圧延方向に対して均一に冷却することができない場合がある。 Moreover, since the cooling of patent document 4 is the cooling of the hot-rolled steel sheet immediately before the finish rolling mill roll bite, it cannot be applied to the hot-rolled steel sheet having a predetermined thickness after finish rolling. Furthermore, Patent Document 4 does not consider the case where a wave shape is formed in the rolling direction of the hot-rolled steel sheet, and as described above, the hot-rolled steel sheet cannot be uniformly cooled in the rolling direction. There is a case.
　また、特許文献５の冷却方法において、上部冷却の冷却能力には、上部注水ノズルから鋼板に供給される冷却水による冷却に加えて、鋼板の上部の乗り水による冷却も含まれる。この乗り水は、鋼板に形成された波形状の急峻度や鋼板の通板速度によって影響されるため、厳密に乗り水による鋼板の冷却能力を特定することはできない。そうすると、上部冷却の冷却能力を正確に制御することが困難である。このため、上部冷却と下部冷却の冷却能力を同一にすることも困難である。しかも、上部冷却と下部冷却の冷却能力を同一にするに際し、これら冷却能力の決定方法の一例は例示されているものの、普遍的な決定方法は開示されていない。したがって、特許文献５の冷却方法は、熱延鋼板を均一に冷却できない場合がある。 Further, in the cooling method of Patent Document 5, the cooling capacity of the upper cooling includes the cooling by the riding water on the upper part of the steel sheet in addition to the cooling by the cooling water supplied to the steel sheet from the upper water injection nozzle. Since this boarding water is influenced by the steepness of the wave shape formed on the steel plate and the plate passing speed of the steel plate, the cooling ability of the steel plate by the boarding water cannot be specified strictly. Then, it is difficult to accurately control the cooling capacity of the upper cooling. For this reason, it is difficult to make the cooling capacity of the upper cooling and the lower cooling the same. Moreover, when the cooling capacity of the upper cooling and the lower cooling is made the same, an example of a method for determining the cooling capacity is illustrated, but a universal determination method is not disclosed. Therefore, the cooling method of patent document 5 may not cool a hot-rolled steel plate uniformly.
本発明は、上述した問題点に鑑みてなされたものであり、仕上圧延機で熱間圧延された熱延鋼板を均一に冷却することを目的とする。 The present invention has been made in view of the above-described problems, and an object thereof is to uniformly cool a hot-rolled steel sheet that has been hot-rolled by a finish rolling mill.
　本発明は、上記課題を解決して係る目的を達成するために以下の手段を採用する。
　すなわち、

（１）本発明の一態様に係る熱延鋼板冷却装置は、仕上圧延機で熱間圧延された熱延鋼板を、その通板経路上に設けられた冷却区間において冷却する熱延鋼板冷却装置であって、前記冷却区間の下流側における前記熱延鋼板の温度を測定する温度計と；前記冷却区間の下流側における前記熱延鋼板の形状を測定する形状計と；前記冷却区間において前記熱延鋼板の上面を冷却する上側冷却装置と；前記冷却区間において前記熱延鋼板の下面を冷却する下側冷却装置と；前記温度計から得られる前記熱延鋼板の温度測定結果と前記形状計から得られる前記熱延鋼板の形状測定結果とに基づいて、前記上側冷却装置及び前記下側冷却装置を制御することにより、前記冷却区間における前記熱延鋼板の上面冷却抜熱量と下面冷却抜熱量との少なくとも一方を制御する制御装置と；を備え、前記制御装置が、前記温度測定結果に基づいて前記冷却区間の下流側における前記熱延鋼板の温度の時系列平均値を平均温度として算出する平均温度算出部と；前記形状測定結果に基づいて前記冷却区間の下流側における前記熱延鋼板の変動速度を算出する変動速度算出部と；前記熱延鋼板の鉛直方向の上向きを正とした場合において、前記変動速度が正の領域で、前記熱延鋼板の波形状１周期以上の範囲の前記平均温度に対して前記熱延鋼板の温度が低い場合は、前記上面冷却抜熱量が減少する方向及び前記下面冷却抜熱量が増加する方向の少なくとも一方を制御方向として決定し、前記平均温度に対して前記熱延鋼板の温度が高い場合は、前記上面冷却抜熱量が増加する方向及び前記下面冷却抜熱量が減少する方向の少なくとも一方を前記制御方向として決定し、前記変動速度が負の領域で、前記平均温度に対して前記熱延鋼板の温度が低い場合は、前記上面冷却抜熱量が増加する方向及び前記下面冷却抜熱量が減少する方向の少なくとも一方を前記制御方向として決定し、前記平均温度に対して前記熱延鋼板の温度が高い場合は、前記上面冷却抜熱量が減少する方向及び前記下面冷却抜熱量が増加する方向の少なくとも一方を前記制御方向として決定する制御方向決定部と；前記制御方向決定部にて決定された前記制御方向に基づいて、前記冷却区間における前記熱延鋼板の前記上面冷却抜熱量と前記下面冷却抜熱量との合計値を調整する冷却抜熱量合計値調整部と；を含む。　 The present invention employs the following means in order to solve the above problems and achieve the object.
That is,

(1) A hot-rolled steel sheet cooling device according to an aspect of the present invention is a hot-rolled steel sheet cooling device that cools a hot-rolled steel sheet hot-rolled by a finish rolling mill in a cooling section provided on the passage plate path. A thermometer for measuring the temperature of the hot-rolled steel sheet downstream of the cooling section; a shape-meter for measuring the shape of the hot-rolled steel sheet downstream of the cooling section; and the heat in the cooling section. An upper cooling device for cooling the upper surface of the rolled steel sheet; a lower cooling device for cooling the lower surface of the hot rolled steel sheet in the cooling section; a temperature measurement result of the hot rolled steel sheet obtained from the thermometer and the shape meter Based on the obtained shape measurement result of the hot-rolled steel sheet, by controlling the upper cooling device and the lower cooling device, the upper surface cooling heat removal amount and the lower surface cooling heat removal amount of the hot rolled steel plate in the cooling section, At least An average temperature calculation for calculating, as an average temperature, a time-series average value of the temperature of the hot-rolled steel sheet on the downstream side of the cooling section based on the temperature measurement result. A fluctuation rate calculation unit that calculates a fluctuation rate of the hot-rolled steel sheet on the downstream side of the cooling section based on the shape measurement result; and when the upward direction in the vertical direction of the hot-rolled steel sheet is positive, When the temperature of the hot-rolled steel sheet is lower than the average temperature in the range of one cycle or more of the wave shape of the hot-rolled steel sheet in a region where the fluctuation speed is positive, the lower surface cooling heat removal amount and the lower surface are reduced. When the temperature of the hot-rolled steel sheet is determined to be at least one of the directions in which the amount of cooling heat removal increases as the control direction and the temperature of the hot-rolled steel sheet is higher than the average temperature, the direction in which the upper surface cooling heat removal amount increases and the lower surface cooling heat removal Is determined as the control direction, and when the temperature of the hot-rolled steel sheet is lower than the average temperature in a region where the fluctuation speed is negative, the amount of heat removal from the upper surface is increased. And at least one of the directions in which the lower surface cooling heat removal amount decreases as the control direction, and when the temperature of the hot-rolled steel sheet is higher than the average temperature, the upper surface cooling heat removal amount decreases and the lower surface A control direction determining unit that determines at least one of the directions in which the amount of heat removal from cooling increases as the control direction; and based on the control direction determined by the control direction determining unit, the hot rolled steel sheet in the cooling section A cooling heat removal amount total value adjustment unit for adjusting a total value of the upper surface cooling heat removal amount and the lower surface cooling heat removal amount.
（２）上記（１）に記載の熱延鋼板冷却装置において、前記熱延鋼板上における前記温度計の温度測定箇所と前記形状計の形状測定箇所との位置ずれが５０ｍｍ以内であることが好ましい。 (2) In the hot-rolled steel sheet cooling device according to the above (1), it is preferable that a positional deviation between the temperature measurement part of the thermometer and the shape measurement part of the shape meter on the hot-rolled steel sheet is within 50 mm. .
（３）上記（１）または（２）に記載の熱延鋼板冷却装置において、前記冷却区間における前記熱延鋼板の通板速度は、５５０ｍ／ｍｉｎ以上から機械的な限界速度以下の範囲内に設定されていることが好ましい。 (3) In the hot-rolled steel sheet cooling device according to (1) or (2) above, the sheet-passing speed of the hot-rolled steel sheet in the cooling section is within a range of 550 m / min or more to a mechanical limit speed or less. It is preferable that it is set.
（４）上記（３）に記載の熱延鋼板冷却装置において、前記熱延鋼板の引張強度は８００ＭＰａ以上であることが好ましい。 (4) In the hot-rolled steel sheet cooling device according to (3) above, the hot-rolled steel sheet preferably has a tensile strength of 800 MPa or more.

（５）上記（３）に記載の熱延鋼板冷却装置において、前記仕上圧延機は複数の圧延スタンドから構成されており、互いに隣合う前記圧延スタンドの間に、前記熱延鋼板の補助冷却を行う補助冷却装置をさらに備えることが好ましい。
(5) In the hot-rolled steel sheet cooling device according to (3), the finish rolling mill is composed of a plurality of rolling stands, and auxiliary cooling of the hot-rolled steel sheets is performed between the rolling stands adjacent to each other. It is preferable to further include an auxiliary cooling device for performing.
本発明の上記態様によれば、熱延鋼板の温度の位相を検出し、その熱延鋼板の波形状と比較することによって、上側冷却能力と下側冷却能力を調整することができ、熱延鋼板の上面冷却抜熱量及び下面冷却抜熱量を調整することができる。したがって、その後、調整された冷却能力で熱延鋼板を冷却することで、その熱延鋼板を均一に冷却することができる。 According to the above aspect of the present invention, the upper cooling capacity and the lower cooling capacity can be adjusted by detecting the phase of the temperature of the hot-rolled steel sheet and comparing it with the wave shape of the hot-rolled steel sheet. The upper surface cooling heat removal amount and the lower surface cooling heat removal amount of the steel sheet can be adjusted. Therefore, after that, the hot-rolled steel sheet can be uniformly cooled by cooling the hot-rolled steel sheet with the adjusted cooling capacity.
本発明の一実施形態における熱延鋼板冷却装置を備えた熱間圧延設備１を示す説明図である。It is explanatory drawing which shows the hot rolling equipment 1 provided with the hot-rolled steel plate cooling device in one Embodiment of this invention. 本実施形態における冷却装置１４の構成の概略を示す説明図である。It is explanatory drawing which shows the outline of a structure of the cooling device 14 in this embodiment. 熱間圧延設備１において冷却装置１４付近の構成の概略を示す説明図である。It is explanatory drawing which shows the outline of a structure of the cooling device 14 vicinity in the hot rolling equipment 1. FIG. 通常の操業における代表的なストリップのＲＯＴ内冷却の熱延鋼板Ｈの温度変動と急峻度の関係を示すグラフであって、上側のグラフは、コイル先端からの距離或いは定点経過時間に対する温度変動を示し、下側のグラフは、コイル先端からの距離または定点経過時間に対する急峻度を示している。A graph showing the relationship between the temperature fluctuation and steepness of a hot-rolled steel sheet H in the ROT cooling of a typical strip in a normal operation, and the upper graph shows the temperature fluctuation with respect to the distance from the coil tip or the fixed point elapsed time. The lower graph shows the steepness with respect to the distance from the coil tip or the fixed point elapsed time. 通常の操業における代表的なストリップのＲＯＴ内冷却の熱延鋼板Ｈの温度変動と急峻度の関係を示すグラフである。It is a graph which shows the relationship between the temperature fluctuation and the steepness of the hot-rolled steel sheet H in the ROT cooling of a typical strip in a normal operation. 熱延鋼板の変動速Ｈ度が正の領域で熱延鋼板Ｈの平均温度に対して熱延鋼板Ｈの温度が低くなり、変動速度が負の領域で熱延鋼板Ｈの温度が高くなった場合に、上面冷却抜熱量を減少させ、下面冷却抜熱量を増加させたときの熱延鋼板Ｈの温度変動と急峻度の関係を示すグラフである。なお、熱延鋼板Ｈの波形状の急峻度とは、波形状の振幅を１周期分の圧延方向の長さで割った値である。The temperature of the hot-rolled steel sheet H is lower than the average temperature of the hot-rolled steel sheet H when the fluctuation speed H degree of the hot-rolled steel sheet is positive, and the temperature of the hot-rolled steel sheet H is higher when the fluctuation speed is negative. In this case, it is a graph showing the relationship between the temperature fluctuation and the steepness of the hot-rolled steel sheet H when the upper surface cooling heat removal amount is decreased and the lower surface cooling heat removal amount is increased. The steepness of the wave shape of the hot-rolled steel sheet H is a value obtained by dividing the amplitude of the wave shape by the length in the rolling direction for one cycle. 熱延鋼板Ｈの変動速度が正の領域で熱延鋼板Ｈの平均温度に対して熱延鋼板Ｈの温度が低く、変動速度が負の領域で熱延鋼板Ｈの温度が高くなった場合に、上面冷却抜熱量を増加させ、下面冷却抜熱量を減少させたときの熱延鋼板Ｈの温度変動と急峻度の関係を示すグラフである。When the temperature of the hot-rolled steel sheet H is lower than the average temperature of the hot-rolled steel sheet H when the fluctuation speed of the hot-rolled steel sheet H is positive, and the temperature of the hot-rolled steel sheet H is higher when the fluctuation speed is negative. FIG. 6 is a graph showing the relationship between the temperature fluctuation and steepness of the hot-rolled steel sheet H when the upper surface cooling heat removal amount is increased and the lower surface cooling heat removal amount is decreased. 熱間圧延設備１において温度計４０と形状計４１の配置を示す説明図である。It is explanatory drawing which shows arrangement | positioning of the thermometer 40 and the shape meter 41 in the hot rolling equipment 1. FIG. 熱間圧延設備１において冷却装置１４の変形例を示す説明図である。It is explanatory drawing which shows the modification of the cooling device 14 in the hot rolling equipment 1. FIG. 熱延鋼板Ｈの急峻度と温度標準偏差との関係を示すグラフである。It is a graph which shows the relationship between the steepness of a hot-rolled steel sheet H, and a temperature standard deviation. 熱延鋼板Ｈの通板速度と温度標準偏差との関係を示すグラフである。It is a graph which shows the relationship between the plate-feeding speed of a hot-rolled steel plate H, and a temperature standard deviation. 熱延鋼板Ｈの板幅方向に温度標準偏差が形成された様子を示す説明図である。It is explanatory drawing which shows a mode that the temperature standard deviation was formed in the plate width direction of the hot-rolled steel plate H. 他の実施形態における熱延鋼板Ｈの冷却方法を実現するための熱間圧延設備２を示す説明図である。It is explanatory drawing which shows the hot rolling equipment 2 for implement | achieving the cooling method of the hot-rolled steel plate H in other embodiment. 熱間圧延設備２において配設される冷却装置１１４の構成の概略を示す説明図である。It is explanatory drawing which shows the outline of a structure of the cooling device 114 arrange | positioned in the hot rolling equipment 2. FIG. 熱延鋼板Ｈの最下点が搬送ロール１３２と接触する様子を示す説明図である。It is explanatory drawing which shows a mode that the lowest point of the hot-rolled steel plate H contacts the conveyance roll 132. FIG. 熱延鋼板Ｈの最下点が搬送ロール１３２及びエプロン１３３と接触する様子を示す説明図である。It is explanatory drawing which shows a mode that the lowest point of the hot-rolled steel plate H contacts with the conveyance roll 132 and the apron 133. FIG. 熱延鋼板Ｈの通板速度が低速の場合における熱延鋼板Ｈの温度の経時変化を示すグラフである。It is a graph which shows the time-dependent change of the temperature of the hot-rolled steel sheet H when the plate-feeding speed of the hot-rolled steel sheet H is low. 熱延鋼板Ｈの通板速度が高速の場合における熱延鋼板Ｈの温度の経時変化を示すグラフである。It is a graph which shows the time-dependent change of the temperature of the hot-rolled steel sheet H when the plate-feeding speed of the hot-rolled steel sheet H is high. スタンド間冷却を行うことが可能な仕上圧延機１１３の説明図である。It is explanatory drawing of the finishing mill 113 which can perform cooling between stands. 従来の熱延鋼板Ｈの製造方法を示す説明図である。It is explanatory drawing which shows the manufacturing method of the conventional hot-rolled steel plate H. 従来の熱延鋼板Ｈの冷却方法を示す説明図である。It is explanatory drawing which shows the cooling method of the conventional hot-rolled steel plate H.
　以下、本発明の実施の形態として、例えば自動車及び産業機械等に使用される熱延鋼板を冷却する熱延鋼板冷却装置について、図面を参照しながら詳細に説明する。 Hereinafter, as an embodiment of the present invention, for example, a hot-rolled steel sheet cooling apparatus for cooling a hot-rolled steel sheet used for automobiles and industrial machines will be described in detail with reference to the drawings.
　図１は、本実施形態における熱延鋼板冷却装置を備えた熱間圧延設備１の例を模式的に示している。この熱間圧延設備１は、加熱したスラブＳをロールで上下に挟んで連続的に圧延し、最小１ｍｍまで薄くしてこれを巻き取ることを目的とした設備である。
この熱間圧延設備１は、スラブＳを加熱するための加熱炉１１と、この加熱炉１１において加熱されたスラブＳを幅方向に圧延する幅方向圧延機１６と、この幅方向に圧延されたスラブＳを上下方向から圧延して粗バーにする粗圧延機１２と、粗バーをさらに所定の厚みまで連続して熱間仕上圧延をする仕上圧延機１３と、この仕上圧延機１３により熱間仕上圧延された熱延鋼板Ｈを冷却水により冷却する冷却装置１４と、冷却装置１４により冷却された熱延鋼板Ｈをコイル状に巻き取る巻取装置１５とを備えている。 FIG. 1 schematically shows an example of a hot rolling facility 1 equipped with a hot-rolled steel sheet cooling device in the present embodiment. This hot rolling facility 1 is a facility intended to continuously roll a heated slab S sandwiched between rolls up and down, thin it to a minimum of 1 mm, and wind it up.
This hot rolling equipment 1 is rolled in the width direction, a heating furnace 11 for heating the slab S, a width-direction rolling mill 16 that rolls the slab S heated in the heating furnace 11 in the width direction, and the width direction. A roughing mill 12 that rolls the slab S from the upper and lower directions to form a rough bar, a finishing mill 13 that continuously hot-rolls the rough bar to a predetermined thickness, and a hot rolling by the finishing mill 13. A cooling device 14 that cools the hot-rolled steel plate H that has been finish-rolled with cooling water, and a winding device 15 that winds the hot-rolled steel plate H cooled by the cooling device 14 into a coil shape are provided.
　加熱炉１１には、装入口を介して外部から搬入されてきたスラブＳに対して、火炎を吹き出すことによりスラブＳを加熱するサイドバーナ、軸流バーナ、ルーフバーナが配設されている。加熱炉１１に搬入されたスラブＳは、各ゾーンにおいて形成される各加熱帯において順次加熱され、さらに最終ゾーンにおいて形成される均熱帯において、ルーフバーナを利用してスラブＳを均等加熱することにより、最適温度で搬送できるようにするための保熱処理を行う。加熱炉１１における加熱処理が全て終了すると、スラブＳは加熱炉１１外へと搬送され、粗圧延機１２による圧延工程へと移行することになる。 The heating furnace 11 is provided with a side burner, an axial flow burner, and a roof burner for heating the slab S by blowing out flames to the slab S carried in from the outside through the loading port. The slab S carried into the heating furnace 11 is sequentially heated in each heating zone formed in each zone, and further in the soaking zone formed in the final zone, the slab S is evenly heated using a roof burner, A coercive heat treatment is performed to enable conveyance at the optimum temperature. When all the heat treatments in the heating furnace 11 are completed, the slab S is transferred to the outside of the heating furnace 11 and moves to a rolling process by the roughing mill 12.
　粗圧延機１２は、搬送されてきたスラブＳにつき、複数スタンドに亘って配設される円柱状の回転ロールの間隙を通過させる。例えば、この粗圧延機１２は、第１スタンドにおいて上下に配設されたワークロール１２ａのみによりスラブＳを熱間圧延して粗バーを形成する。次に、このワークロール１２ａを通過した粗バーをワークロールとバックアップロールとにより構成される複数の４重圧延機１２ｂによりさらに連続的に圧延する。その結果、この粗圧延工程の終了時に、粗バーは、厚さ３０～６０ｍｍ程度まで圧延され、仕上圧延機１３へと搬送されることになる。 The rough rolling mill 12 allows the slab S that has been conveyed to pass through a gap between cylindrical rotary rolls that are disposed across a plurality of stands. For example, this roughing mill 12 hot-rolls the slab S only by the work rolls 12a arranged up and down in the first stand to form a rough bar. Next, the rough bar that has passed through the work roll 12a is further continuously rolled by a plurality of quadruple rolling mills 12b constituted by the work roll and the backup roll. As a result, at the end of the rough rolling step, the rough bar is rolled to a thickness of about 30 to 60 mm and conveyed to the finishing mill 13.
　仕上圧延機１３は、粗圧延機１２から搬送されてきた粗バーを、その厚さが数ｍｍ程度になるまで仕上げ圧延する。これら仕上圧延機１３は、６～７スタンドに亘って上下一直線に並べられた仕上げ圧延ロール１３ａの間隙に粗バーを通過させ、これを徐々に圧下していく。この仕上圧延機１３により仕上げ圧延された熱延鋼板Ｈは、後述する搬送ロール３２によって冷却装置１４へと搬送される。 The finish rolling mill 13 finish-rolls the coarse bar conveyed from the rough rolling mill 12 until the thickness becomes about several mm. These finish rolling mills 13 allow the coarse bar to pass through the gaps between the finish rolling rolls 13a arranged in a straight line over 6 to 7 stands, and gradually reduce them. The hot-rolled steel sheet H finish-rolled by the finish rolling mill 13 is conveyed to the cooling device 14 by a conveyance roll 32 described later.
　冷却装置１４は、仕上圧延機１３から搬送される熱延鋼板Ｈに対していわゆるラミナー冷却を施すための設備である。この冷却装置１４は、図２に示すように、ランナウトテーブルの搬送ロール３２上を移動する熱延鋼板Ｈの上面に対して、上側の冷却口３１から冷却水を噴射する上側冷却装置１４ａと、熱延鋼板Ｈの下面に対して、下側の冷却口３１から冷却水を噴射する下側冷却装置１４ｂとを備えている。冷却口３１は、上側冷却装置１４ａ及び下側冷却装置１４ｂのそれぞれについて複数個設けられている。
また、冷却口３１には、冷却ヘッダー（図示省略）が接続されている。この冷却口３１の個数によって、上側冷却装置１４ａ及び下側冷却装置１４ｂの冷却能力が決定される。なお、この冷却装置１４は、上下スプリットラミナー、パイプラミナー、スプレー冷却等の少なくとも一つで構成されていてもよい。また、この冷却装置１４によって熱延鋼板Ｈが冷却される区間が、本発明における冷却区間に相当する。 The cooling device 14 is equipment for applying so-called laminar cooling to the hot-rolled steel sheet H conveyed from the finish rolling mill 13. As shown in FIG. 2, the cooling device 14 has an upper cooling device 14 a that jets cooling water from the upper cooling port 31 to the upper surface of the hot-rolled steel sheet H that moves on the transport roll 32 of the run-out table, The lower side cooling device 14b which injects a cooling water from the lower side cooling port 31 with respect to the lower surface of the hot-rolled steel plate H is provided. A plurality of cooling ports 31 are provided for each of the upper cooling device 14a and the lower cooling device 14b.
A cooling header (not shown) is connected to the cooling port 31. The cooling capacity of the upper cooling device 14a and the lower cooling device 14b is determined by the number of the cooling ports 31. The cooling device 14 may be composed of at least one of an upper / lower split laminar, a pipe laminar, spray cooling, and the like. Further, a section in which the hot-rolled steel sheet H is cooled by the cooling device 14 corresponds to a cooling section in the present invention.
　また、図３に示すように、冷却区間（つまり冷却装置１４）の下流側には、熱延鋼板Ｈの圧延方向に定められた測定位置の温度を測定する温度計４０と、温度計４０と同一測定位置の熱延鋼板Ｈの波形状を測定する形状計４１とが配置されている。
　これら温度計４０及び形状計４１は、ケーブル等を介して制御装置５０と電気的に接続されている。また、制御装置５０は、ケーブル等を介して上側冷却装置１４ａ及び下側冷却装置１４ｂと電気的に接続されている。
　温度計４０は、熱延鋼板Ｈの温度測定結果を制御装置５０に出力する。形状計４１は、熱延鋼板Ｈの形状測定結果を制御装置５０に出力する。
　制御装置５０は、温度計４０から得られる温度測定結果と形状計４１から得られる形状測定結果とに基づいて、上側冷却装置１４ａ及び下側冷却装置１４ｂを制御することにより、冷却区間における熱延鋼板Ｈの上面冷却抜熱量と下面冷却抜熱量との少なくとも一方を制御する。
　この制御装置５０は、プログラムの実行によって実現される機能として、平均温度算出部５１、変動速度算出部５２、制御方向決定部５３及び冷却抜熱量合計値調整部５４を備えている。これら各機能部の役割については後述する。 Further, as shown in FIG. 3, on the downstream side of the cooling section (that is, the cooling device 14), a thermometer 40 that measures the temperature at a measurement position determined in the rolling direction of the hot-rolled steel sheet H, A shape meter 41 for measuring the wave shape of the hot-rolled steel sheet H at the same measurement position is arranged.
The thermometer 40 and the shape meter 41 are electrically connected to the control device 50 via a cable or the like. The control device 50 is electrically connected to the upper cooling device 14a and the lower cooling device 14b via a cable or the like.
The thermometer 40 outputs the temperature measurement result of the hot-rolled steel sheet H to the control device 50. The shape meter 41 outputs the shape measurement result of the hot-rolled steel sheet H to the control device 50.
The control device 50 controls the upper cooling device 14a and the lower cooling device 14b on the basis of the temperature measurement result obtained from the thermometer 40 and the shape measurement result obtained from the shape meter 41, thereby performing hot rolling in the cooling section. At least one of the upper surface cooling heat removal amount and the lower surface cooling heat removal amount of the steel sheet H is controlled.
The control device 50 includes an average temperature calculation unit 51, a fluctuation speed calculation unit 52, a control direction determination unit 53, and a cooling heat removal total value adjustment unit 54 as functions realized by executing the program. The role of each functional unit will be described later.
巻取装置１５は、図１に示すように、冷却装置１４により冷却された熱延鋼板Ｈを所定の巻取温度で巻き取る。巻取装置１５によりコイル状に巻き取られた熱延鋼板Ｈは、熱間圧延設備１外へと搬送されることになる。
　なお、上記のように構成された熱間圧延設備１において、上側冷却装置１４ａ、下側冷却装置１４ｂ、温度計４０、形状計４１及び制御装置５０が、本実施形態における熱延鋼板冷却装置を構成している。 As shown in FIG. 1, the winding device 15 winds the hot rolled steel sheet H cooled by the cooling device 14 at a predetermined winding temperature. The hot-rolled steel sheet H wound up in a coil shape by the winding device 15 is conveyed outside the hot rolling facility 1.
In the hot rolling facility 1 configured as described above, the upper cooling device 14a, the lower cooling device 14b, the thermometer 40, the shape meter 41, and the control device 50 are the hot-rolled steel sheet cooling device in the present embodiment. It is composed.
　次に、上記のように構成された熱間圧延設備１によって実現される熱延鋼板Ｈの冷却方法について説明する。
なお、以下の説明において、仕上圧延機１３で熱間圧延された熱延鋼板Ｈには、図１９に示すように、その圧延方向に表面高さ（波高さ）が変動する波形状が形成されている。また、以下の説明において、熱延鋼板Ｈの冷却時に、その熱延鋼板Ｈ上に溜まる乗り水の影響は無視する。実際に、本願発明者による調査の結果、熱延鋼板Ｈ上に溜まる乗り水の影響はほとんどないことがわかっている。 Next, the cooling method of the hot-rolled steel sheet H realized by the hot rolling facility 1 configured as described above will be described.
In the following description, as shown in FIG. 19, a corrugated shape whose surface height (wave height) fluctuates in the rolling direction is formed on the hot-rolled steel sheet H that has been hot-rolled by the finish mill 13. ing. Moreover, in the following description, the influence of the running water which accumulates on the hot-rolled steel sheet H when the hot-rolled steel sheet H is cooled is ignored. Actually, as a result of the investigation by the inventor of the present application, it has been found that there is almost no influence of the running water accumulated on the hot-rolled steel sheet H.
　先ず、冷却装置１４で熱延鋼板Ｈを冷却する前に、予め冷却装置１４の上側冷却装置１４ａの冷却能力（上側冷却能力）と下側冷却装置１４ｂの冷却能力（下側冷却能力）をそれぞれ調整する。これら上側冷却能力と下側冷却能力は、それぞれ上側冷却装置１４ａによって冷却される熱延鋼板Ｈの上面の熱伝達係数と、下側冷却装置１４ｂによって冷却される熱延鋼板Ｈの下面の熱伝達係数とを用いて調整する。 First, before cooling the hot-rolled steel sheet H with the cooling device 14, the cooling capacity (upper cooling capacity) of the upper cooling device 14a of the cooling apparatus 14 and the cooling capacity (lower cooling capacity) of the lower cooling device 14b are previously set. adjust. The upper cooling capacity and the lower cooling capacity are respectively the heat transfer coefficient of the upper surface of the hot rolled steel sheet H cooled by the upper cooling device 14a and the heat transfer of the lower surface of the hot rolled steel sheet H cooled by the lower cooling device 14b. Adjust using the coefficient.
　ここで、熱延鋼板Ｈの上面と下面の熱伝達係数の算出方法について説明する。熱伝達係数は、単位面積からの単位時間当たりの冷却抜熱量（熱エネルギー）を、被熱伝達体と熱媒体との温度差で除した値である（熱伝達係数＝冷却抜熱量／温度差）。ここでの温度差は、冷却装置１４の入口側の温度計によって測定される熱延鋼板Ｈの温度と、冷却装置１４で用いられる冷却水の温度との差である。
また、冷却抜熱量は、熱延鋼板Ｈの温度差と比熱と質量をそれぞれ乗じた値である（冷却抜熱量＝温度差×比熱×質量）。すなわち、冷却抜熱量は冷却装置１４における熱延鋼板Ｈの冷却抜熱量であって、冷却装置１４の入口側の温度計と出口側の温度計によってそれぞれ測定される熱延鋼板Ｈの温度の差と、熱延鋼板Ｈの比熱と、冷却装置１４で冷却される熱延鋼板Ｈの質量とをそれぞれ乗じた値である。 Here, the calculation method of the heat transfer coefficient of the upper surface and the lower surface of the hot-rolled steel sheet H will be described. The heat transfer coefficient is a value obtained by dividing the amount of heat removed from cooling (heat energy) per unit time from the unit area by the temperature difference between the heat transfer medium and the heat medium (heat transfer coefficient = cooled heat removal / temperature difference). ). The temperature difference here is a difference between the temperature of the hot-rolled steel sheet H measured by the thermometer on the inlet side of the cooling device 14 and the temperature of the cooling water used in the cooling device 14.
The cooling heat removal amount is a value obtained by multiplying the temperature difference, specific heat, and mass of the hot-rolled steel sheet H (cooling heat removal amount = temperature difference × specific heat × mass). That is, the amount of heat removed from cooling is the amount of heat removed from the hot-rolled steel sheet H in the cooling device 14, and the difference in temperature between the hot-rolled steel plates H measured by the thermometer on the inlet side and the thermometer on the outlet side of the cooling device 14. And the specific heat of the hot-rolled steel sheet H and the mass of the hot-rolled steel sheet H cooled by the cooling device 14, respectively.
　上述のように算出された熱延鋼板Ｈの熱伝達係数は、熱延鋼板Ｈの上面と下面の熱伝達係数に分けられる。これら上面と下面の熱伝達係数は、例えば次のようにして予め得られる比率を用いて算出される。
すなわち、上側冷却装置１４ａのみで熱延鋼板Ｈを冷却する場合の熱延鋼板Ｈの熱伝達係数と、下側冷却装置１４ｂのみで熱延鋼板Ｈを冷却する場合の熱延鋼板Ｈの熱伝達係数を測定する。
このとき、上側冷却装置１４ａからの冷却水量と下側冷却装置１４ｂからの冷却水量を同一とする。測定された上側冷却装置１４ａを用いた場合の熱伝達係数と下側冷却装置１４ｂを用いた場合の熱伝達係数との比率の逆数が、上下熱伝達係数比率を“１”とする場合の上側冷却装置１４ａからの冷却水量と下側冷却装置１４ｂからの冷却水量との上下比率となる。
そして、このようにして得られた冷却水量の上下比率を、熱延鋼板Ｈを冷却する際の上側冷却装置１４ａからの冷却水量又は下側冷却装置１４ｂからの冷却水量に乗じて、上述した熱延鋼板Ｈの上面と下面の熱伝達係数の比率を算出する。
また、上述では、上側冷却装置１４ａのみと下側冷却装置１４ｂのみで冷却される熱延鋼板Ｈの熱伝達係数を用いたが、上側冷却装置１４ａと下側冷却装置１４ｂの両方で冷却される熱延鋼板Ｈの熱伝達係数を用いてもよい。すなわち、上側冷却装置１４ａと下側冷却装置１４ｂの冷却水量を変更した場合の熱延鋼板Ｈの熱伝達係数を測定し、その熱伝達係数の比率を用いて熱延鋼板Ｈの上面と下面の熱伝達係数の比率を算出してもよい。 The heat transfer coefficient of the hot-rolled steel sheet H calculated as described above is divided into the heat transfer coefficients of the upper surface and the lower surface of the hot-rolled steel sheet H. These heat transfer coefficients of the upper surface and the lower surface are calculated using, for example, a ratio obtained in advance as follows.
That is, the heat transfer coefficient of the hot-rolled steel sheet H when the hot-rolled steel sheet H is cooled only by the upper cooling device 14a and the heat transfer of the hot-rolled steel plate H when the hot-rolled steel plate H is cooled only by the lower cooling device 14b. Measure the coefficient.
At this time, the cooling water amount from the upper cooling device 14a and the cooling water amount from the lower cooling device 14b are the same. The reciprocal of the ratio of the measured heat transfer coefficient when using the upper cooling device 14a and the heat transfer coefficient when using the lower cooling device 14b is the upper side when the upper and lower heat transfer coefficient ratio is “1”. This is the vertical ratio between the amount of cooling water from the cooling device 14a and the amount of cooling water from the lower cooling device 14b.
Then, the above-described heat ratio is obtained by multiplying the vertical ratio of the cooling water amount thus obtained by the cooling water amount from the upper cooling device 14a when cooling the hot-rolled steel sheet H or the cooling water amount from the lower cooling device 14b. The ratio of the heat transfer coefficient between the upper surface and the lower surface of the rolled steel sheet H is calculated.
In the above description, the heat transfer coefficient of the hot-rolled steel sheet H that is cooled only by the upper cooling device 14a and the lower cooling device 14b is used. However, it is cooled by both the upper cooling device 14a and the lower cooling device 14b. The heat transfer coefficient of the hot-rolled steel sheet H may be used. That is, the heat transfer coefficient of the hot-rolled steel sheet H when the amount of cooling water of the upper cooling device 14a and the lower cooling device 14b is changed is measured, and the ratio of the heat transfer coefficient is used to determine the upper and lower surfaces of the hot-rolled steel sheet H. The ratio of the heat transfer coefficient may be calculated.
　以上のように、熱延鋼板Ｈの熱伝達係数を算出し、熱延鋼板Ｈの上面と下面の熱伝達係数の上記比率（上下熱伝達係数比率）に基づいて、熱延鋼板Ｈの上面と下面の熱伝達係数が算出される。 As described above, the heat transfer coefficient of the hot-rolled steel sheet H is calculated, and the upper surface of the hot-rolled steel sheet H is calculated based on the above ratio (upper and lower heat transfer coefficient ratio) of the heat transfer coefficients of the upper and lower surfaces of the hot-rolled steel sheet H. The heat transfer coefficient of the lower surface is calculated.
　ここで、熱延鋼板Ｈを均一に冷却するために、上側冷却装置１４ａと下側冷却装置１４ｂの冷却能力を調整する（熱延鋼板Ｈの上面冷却抜熱量と下面冷却抜熱量とを制御する）ことについて、本願発明者らが鋭意検討した結果、さらに、以下の知見を得るに至った。 Here, in order to uniformly cool the hot-rolled steel sheet H, the cooling capacity of the upper cooling device 14a and the lower cooling device 14b is adjusted (the upper surface cooling heat removal amount and the lower surface cooling heat removal amount of the hot rolled steel plate H are controlled. As a result of intensive studies by the inventors of the present invention, the following knowledge has been obtained.
　本願発明者らは、熱延鋼板Ｈの波形状が発生した状態での冷却によって発生した温度標準偏差の特徴について鋭意検討を重ねて来た結果、次の事を明らかにした。 The inventors of the present application have made intensive studies on the characteristics of the temperature standard deviation generated by cooling in the state where the wave shape of the hot-rolled steel sheet H is generated, and as a result, have clarified the following.
　通板中の熱延鋼板Ｈに対し、温度計４０と形状計４１によって熱延鋼板Ｈの圧延方向に定められた測定位置（以下では、この測定位置を定点と呼ぶ場合がある）の温度測定及び形状測定を一定の時間間隔（サンプリング間隔）で行い、温度測定結果及び形状測定結果の時系列データを取得する。
なお、温度計４０による温度の測定領域は、熱延鋼板Ｈの幅方向の全域を含む。また、形状とは、定点測定で観測される熱延鋼板Ｈの高さ方向の変動量に熱延鋼板Ｈの通板方向の移動量を用いて、波のピッチ分の高さ或いは変動成分の線積分で求めた急峻度である。また、同時に単位時間当たりの変動量、即ち変動速度も求める。さらに、形状の測定領域は、温度の測定領域と同様に、熱延鋼板Ｈの幅方向の全域を含む。また、各測定結果のサンプリング時間に熱延鋼板Ｈの通板速度（搬送速度）を乗算すると、各測定結果が得られた熱延鋼板Ｈの圧延方向の位置を算出することができる。つまり、各測定結果の時系列データがサンプリングされた時間に通板速度を乗じると、各測定結果の時系列データを圧延方向の位置に紐付けすることが可能となる。 Temperature measurement at a measurement position (hereinafter, this measurement position may be referred to as a fixed point) determined in the rolling direction of the hot-rolled steel sheet H by the thermometer 40 and the shape meter 41 with respect to the hot-rolled steel sheet H in the plate. The shape measurement is performed at a constant time interval (sampling interval), and the temperature measurement result and the time series data of the shape measurement result are acquired.
Note that the temperature measurement region by the thermometer 40 includes the entire width direction of the hot-rolled steel sheet H. In addition, the shape refers to the height or fluctuation component of the wave pitch by using the amount of movement in the sheet passing direction of the hot-rolled steel sheet H as the amount of fluctuation in the height direction of the hot-rolled steel sheet H observed by fixed point measurement. This is the steepness obtained by line integration. At the same time, the fluctuation amount per unit time, that is, the fluctuation speed is also obtained. Furthermore, the shape measurement region includes the entire region in the width direction of the hot-rolled steel sheet H, similarly to the temperature measurement region. Moreover, when the sampling time of each measurement result is multiplied by the sheet feeding speed (conveying speed) of the hot-rolled steel sheet H, the position in the rolling direction of the hot-rolled steel sheet H from which each measurement result is obtained can be calculated. That is, when the time at which the time series data of each measurement result is sampled is multiplied by the sheet feeding speed, the time series data of each measurement result can be linked to the position in the rolling direction.
　この時系列データを用いて、先ず、熱延鋼板Ｈの上面冷却抜熱量と下面冷却抜熱量との合計値を調整する。具体的には、温度計４０で測定される温度の時系列平均値が所定の目標値に一致するように、熱延鋼板Ｈの上面冷却抜熱量と下面冷却抜熱量との合計値を調整する。
そして、上面冷却抜熱量と下面冷却抜熱量との合計値を調整する時には、例えば三塚の式等に代表される実験理論式を用いて予め求められた理論値に対して、実際の操業実績との誤差を補正する様に設定した学習値に基づき、冷却装置１４に接続される冷却ヘッダーのオンオフ制御を行っても良い。或いは、実際に温度計４０で測定された温度に基づいて、上記冷却ヘッダーのオンオフをフィードバック制御又はフィードフォワード制御してもよい。 Using this time series data, first, the total value of the upper surface cooling heat removal amount and the lower surface cooling heat removal amount of the hot-rolled steel sheet H is adjusted. Specifically, the total value of the upper surface cooling heat removal amount and the lower surface cooling heat removal amount of the hot-rolled steel sheet H is adjusted so that the time-series average value of the temperature measured by the thermometer 40 matches a predetermined target value. .
And when adjusting the total value of the upper surface cooling heat removal amount and the lower surface cooling heat removal amount, for example, with respect to the theoretical value obtained in advance using an experimental theoretical formula typified by Mitsuka's formula, On / off control of the cooling header connected to the cooling device 14 may be performed based on a learning value set so as to correct the error. Alternatively, on / off of the cooling header may be feedback-controlled or feed-forward controlled based on the temperature actually measured by the thermometer 40.
　次に、上述した温度計４０と形状計４１から得られるデータを用いて従来のＲＯＴの冷却制御について説明をする。図４は、通常の操業における代表的なストリップのＲＯＴ内冷却の熱延鋼板Ｈの温度変動と急峻度の関係を示している。図４における熱延鋼板Ｈの上下熱伝達係数比率は１．２：１であり、上側冷却能力が下側冷却能力よりも高くなっている。図４の上側のグラフは、コイル先端からの距離或いは定点経過時間に対する温度変動を示し、図４の下側のグラフは、コイル先端からの距離または定点経過時間に対する急峻度を示している。
図４における領域Ａは、図３に示すストリップ先端部が巻取装置１５のコイラーに噛み込まれる前の領域（張力が無い為、形状が悪い領域）である。図４における領域Ｂは、ストリップ先端部がコイラーに噛み込まれた後の領域（ユニットテンションの影響で波形状がフラットに変化する領域）である。このような熱延鋼板Ｈの形状がフラットでない領域で発生する大きな温度変動（つまり温度標準偏差）を改善することが望まれる。 Next, conventional cooling control of the ROT will be described using data obtained from the thermometer 40 and the shape meter 41 described above. FIG. 4 shows the relationship between the temperature fluctuation and steepness of the hot-rolled steel sheet H that is cooled in the ROT of a typical strip in a normal operation. The upper and lower heat transfer coefficient ratio of the hot-rolled steel sheet H in FIG. 4 is 1.2: 1, and the upper cooling capacity is higher than the lower cooling capacity. The upper graph in FIG. 4 shows the temperature variation with respect to the distance from the coil tip or the fixed point elapsed time, and the lower graph in FIG. 4 shows the distance from the coil tip or the steepness with respect to the fixed point elapsed time.
A region A in FIG. 4 is a region before the strip front end portion shown in FIG. 3 is bitten by the coiler of the winding device 15 (a region having a bad shape because there is no tension). A region B in FIG. 4 is a region after the strip tip portion is bitten by the coiler (a region where the wave shape is changed flat due to the influence of the unit tension). It is desired to improve a large temperature fluctuation (that is, temperature standard deviation) generated in a region where the shape of the hot-rolled steel sheet H is not flat.
　そこで、本願発明者らは、ＲＯＴにおける温度標準偏差の増大を抑制することを目標として、鋭意実験を行ってきた結果、以下のような知見を得るに至った。 Accordingly, the inventors of the present application have conducted intensive experiments with the goal of suppressing an increase in temperature standard deviation in the ROT, and as a result, have obtained the following knowledge.
　図５は、図４と同様に通常の操業における代表的なストリップのＲＯＴ内冷却の同一形状急峻度に対する温度変動成分を示している。この温度変動成分とは、実際の鋼板温度から温度の時系列平均（以下、「平均温度」という場合がある）を引いた残差である。例えば平均温度は、熱延鋼板Ｈの波形状１周期以上の範囲を平均としても良い。
なお、平均温度は、原則として周期単位での範囲の平均である。また、１周期の範囲の平均温度は、２周期以上の範囲の平均温度と大きな差がないことが操業データによって確認されている。
従って、少なくとも波形状１周期の範囲の平均温度を算出すればよい。熱延鋼板Ｈの波形状の範囲の上限は特に限定されないが、好ましくは５周期に設定すれば、十分な精度の平均温度を得られる。また、平均する範囲が周期単位の範囲でなくとも、２～５周期の範囲であれば許容できる平均温度を得られる。 FIG. 5 shows the temperature fluctuation component with respect to the same shape steepness of cooling in the ROT of a typical strip in a normal operation as in FIG. This temperature fluctuation component is a residual obtained by subtracting a time-series average of temperature (hereinafter sometimes referred to as “average temperature”) from the actual steel plate temperature. For example, the average temperature may be averaged over a range of one or more wave shapes of the hot-rolled steel sheet H.
The average temperature is in principle the average of the range in units of cycles. In addition, it has been confirmed by the operation data that the average temperature in the range of one cycle is not significantly different from the average temperature in the range of two cycles or more.
Therefore, it is only necessary to calculate an average temperature in a range of at least one waveform. The upper limit of the corrugated range of the hot-rolled steel sheet H is not particularly limited, but preferably an average temperature with sufficient accuracy can be obtained if it is set to 5 cycles. Further, even if the range to be averaged is not a cycle unit range, an acceptable average temperature can be obtained if it is in the range of 2 to 5 cycles.
　ここで、熱延鋼板Ｈの鉛直方向（熱延鋼板Ｈの上下面に直交する方向）の上向きを正とすると、定点で測定された変動速度が正の領域で、熱延鋼板Ｈの波形状１周期以上の範囲の平均温度に対して熱延鋼板Ｈの温度（定点で測定された温度）が低い場合は、上面冷却抜熱量が減少する方向及び下面冷却抜熱量が増加する方向の少なくとも一方を制御方向として決定し、上記の平均温度に対して熱延鋼板Ｈの温度が高い場合は、上面冷却抜熱量が増加する方向及び下面冷却抜熱量が減少する方向の少なくとも一方を制御方向として決定する。
また、定点で測定された変動速度が負の領域で、上記の平均温度に対して熱延鋼板Ｈの温度が低い場合は、上面冷却抜熱量が増加する方向及び下面冷却抜熱量が減少する方向の少なくとも一方を制御方向として決定し、上記の平均温度に対して熱延鋼板Ｈの温度が高い場合は、上面冷却抜熱量が減少する方向及び下面冷却抜熱量が増加する方向の少なくとも一方を制御方向として決定する。
そして、上記のように決定された制御方向に基づいて、冷却区間における熱延鋼板Ｈの上面冷却抜熱量及び下面冷却抜熱量の少なくとも一方を調整すると、図６に示すように、図５と比較して、熱延鋼板Ｈの形状がフラットでない領域Ａで発生する温度変動を低減できることがわかった。 Here, when the upward direction in the vertical direction of the hot-rolled steel sheet H (direction perpendicular to the upper and lower surfaces of the hot-rolled steel sheet H) is positive, the wave shape of the hot-rolled steel sheet H is a region where the fluctuation rate measured at a fixed point is positive. When the temperature of the hot-rolled steel sheet H (temperature measured at a fixed point) is lower than the average temperature in the range of one cycle or more, at least one of the direction in which the upper surface cooling heat removal amount decreases and the direction in which the lower surface cooling heat removal amount increases. Is determined as the control direction, and when the temperature of the hot-rolled steel sheet H is higher than the average temperature, at least one of the direction in which the upper surface cooling heat removal amount increases and the direction in which the lower surface cooling heat removal amount decreases is determined as the control direction. To do.
Further, when the temperature of the hot-rolled steel sheet H is lower than the above average temperature in the region where the fluctuation rate measured at a fixed point is negative, the direction in which the upper surface cooling heat removal amount increases and the direction in which the lower surface cooling heat removal amount decreases. Is determined as a control direction, and when the temperature of the hot-rolled steel sheet H is higher than the above average temperature, at least one of the direction in which the upper surface cooling heat removal amount decreases and the direction in which the lower surface cooling heat removal amount increases is controlled. Determine as direction.
Then, when at least one of the upper surface cooling heat removal amount and the lower surface cooling heat removal amount of the hot-rolled steel sheet H in the cooling section is adjusted based on the control direction determined as described above, as shown in FIG. And it turned out that the temperature fluctuation generate | occur | produced in the area | region A where the shape of the hot-rolled steel plate H is not flat can be reduced.
　上記とは逆の操作を行った場合について以下に記す。定点で測定された変動速度が正の領域で、熱延鋼板Ｈの平均温度に対して熱延鋼板Ｈの温度が低い場合は、上面冷却抜熱量が増加する方向及び下面冷却抜熱量が減少する方向の少なくとも一方を制御方向として決定し、上記の平均温度に対して熱延鋼板Ｈの温度が高い場合は、上面冷却抜熱量が減少する方向及び下面冷却抜熱量が増加する方向の少なくとも一方を制御方向として決定する。
また、定点で測定された変動速度が負の領域で、上記の平均温度に対して熱延鋼板Ｈの温度が低い場合は、上面冷却抜熱量が減少する方向及び下面冷却抜熱量が増加する方向の少なくとも一方を制御方向として決定し、上記の平均温度に対して熱延鋼板Ｈの温度が高い場合は、上面冷却抜熱量が増加する方向及び下面冷却抜熱量が減少する方向の少なくとも一方を制御方向として決定する。
そして、上記のように決定された制御方向に基づいて、冷却区間における熱延鋼板Ｈの上面冷却抜熱量及び下面冷却抜熱量の少なくとも一方を調整すると、図７に示すように、図５と比較して、熱延鋼板Ｈの形状がフラットでない領域Ａで発生する温度変動が拡大することがわかった。なお、ここで説明する例でも冷却停止温度を変えてよいという前提にはなっていない。 The case where the reverse operation is performed will be described below. When the temperature of the hot-rolled steel sheet H is lower than the average temperature of the hot-rolled steel sheet H in a region where the fluctuation rate measured at a fixed point is positive, the direction in which the upper surface cooling heat removal amount increases and the lower surface cooling heat removal amount decreases. When at least one of the directions is determined as the control direction and the temperature of the hot-rolled steel sheet H is higher than the average temperature, at least one of the direction in which the upper surface cooling heat removal amount decreases and the direction in which the lower surface cooling heat removal amount increases is determined. Determine as the control direction.
Further, when the temperature of the hot-rolled steel sheet H is lower than the above average temperature in a region where the fluctuation rate measured at a fixed point is negative, the direction in which the upper surface cooling heat removal amount decreases and the direction in which the lower surface cooling heat removal amount increases. Is determined as a control direction, and when the temperature of the hot-rolled steel sheet H is higher than the above average temperature, at least one of the direction in which the upper surface cooling heat removal amount increases and the direction in which the lower surface cooling heat removal amount decreases is controlled. Determine as direction.
Then, when at least one of the upper surface cooling heat removal amount and the lower surface cooling heat removal amount of the hot-rolled steel sheet H in the cooling section is adjusted based on the control direction determined as described above, as shown in FIG. And it turned out that the temperature fluctuation which generate | occur | produces in the area | region A where the shape of the hot-rolled steel plate H is not flat expands. In the example described here, it is not assumed that the cooling stop temperature may be changed.
　この関係を利用すれば、温度変動、つまり温度標準偏差を低減させるために、冷却装置１４の上側冷却装置１４ａと下側冷却装置１４ｂのどちらの冷却能力を調整すればよいのかが明確になる。なお、表１は上記関係をまとめた表である。 Using this relationship, it becomes clear which cooling capacity of the upper cooling device 14a or the lower cooling device 14b of the cooling device 14 should be adjusted in order to reduce the temperature fluctuation, that is, the temperature standard deviation. Table 1 summarizes the above relationships.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　本実施形態の熱延鋼板冷却装置は、上述した冷却方法を実現するものである。すなわち、制御装置５０の平均温度算出部５１は、温度計４０から時系列的に得られる温度測定結果の時系列平均値を平均温度として算出する。また、変動速度算出部５２は、形状計４１から時系列的に得られる形状測定結果に基づいて、熱延鋼板Ｈの変動速度を算出する。
　制御方向決定部５３は、熱延鋼板Ｈの鉛直方向の上向きを正とすると、定点で測定された変動速度が正の領域で、熱延鋼板Ｈの波形状１周期以上の範囲の平均温度に対して熱延鋼板Ｈの温度（定点で測定された温度）が低い場合は、上面冷却抜熱量が減少する方向及び下面冷却抜熱量が増加する方向の少なくとも一方を制御方向として決定し、上記の平均温度に対して熱延鋼板Ｈの温度が高い場合は、上面冷却抜熱量が増加する方向及び下面冷却抜熱量が減少する方向の少なくとも一方を制御方向として決定する。
　また、制御方向決定部５３は、定点で測定された変動速度が負の領域で、上記の平均温度に対して熱延鋼板Ｈの温度が低い場合は、上面冷却抜熱量が増加する方向及び下面冷却抜熱量が減少する方向の少なくとも一方を制御方向として決定し、上記の平均温度に対して熱延鋼板Ｈの温度が高い場合は、上面冷却抜熱量が減少する方向及び下面冷却抜熱量が増加する方向の少なくとも一方を制御方向として決定する。
　そして、冷却抜熱量合計値調整部５４は、上記のように決定された制御方向に基づいて、冷却区間における熱延鋼板Ｈの上面冷却抜熱量と下面冷却抜熱量との合計値を調整する。 The hot-rolled steel sheet cooling device of the present embodiment realizes the cooling method described above. That is, the average temperature calculation unit 51 of the control device 50 calculates the time series average value of the temperature measurement results obtained from the thermometer 40 in time series as the average temperature. Further, the fluctuation speed calculation unit 52 calculates the fluctuation speed of the hot-rolled steel sheet H based on the shape measurement results obtained from the shape meter 41 in time series.
If the upward direction in the vertical direction of the hot-rolled steel sheet H is positive, the control direction determining unit 53 is an area where the fluctuation rate measured at a fixed point is positive, and the average temperature in the range of one or more wave shapes of the hot-rolled steel sheet H is obtained. On the other hand, when the temperature of the hot-rolled steel sheet H (temperature measured at a fixed point) is low, at least one of the direction in which the upper surface cooling heat removal amount decreases and the direction in which the lower surface cooling heat removal amount increases is determined as the control direction. When the temperature of the hot-rolled steel sheet H is higher than the average temperature, at least one of the direction in which the upper surface cooling heat removal amount increases and the direction in which the lower surface cooling heat removal amount decreases is determined as the control direction.
In addition, the control direction determination unit 53 is a region where the fluctuation rate measured at a fixed point is negative, and when the temperature of the hot-rolled steel sheet H is lower than the above average temperature, the upper surface cooling heat removal amount increases and the lower surface. When the temperature of the hot-rolled steel sheet H is determined to be at least one of the directions in which the cooling heat removal amount decreases as the control direction and the above-mentioned average temperature is higher, the upper surface cooling heat removal amount decreases and the lower surface cooling heat removal amount increases. At least one of the directions to be determined is determined as the control direction.
And the cooling heat removal amount total value adjustment part 54 adjusts the total value of the upper surface cooling heat removal amount and the lower surface cooling heat removal amount of the hot-rolled steel sheet H in a cooling area based on the control direction determined as mentioned above.
　なお、上側冷却装置１４ａの冷却能力と下側冷却装置１４ｂの冷却能力を調整する際には、例えば上側冷却装置１４ａの冷却口３１に接続される冷却ヘッダーと下側冷却装置１４ｂの冷却口３１に接続される冷却ヘッダーとを、それぞれオンオフ制御してもよい。あるいは、上側冷却装置１４ａと下側冷却装置１４ｂにおける各冷却ヘッダーの冷却能力を制御してもよい。すなわち、各冷却口３１から噴射される冷却水の水量密度、圧力、水温の少なくとも一つを調整してもよい。
また、上側冷却装置１４ａと下側冷却装置１４ｂの冷却ヘッダー（冷却口３１）を間引いて、上側冷却装置１４ａと下側冷却装置１４ｂから噴射される冷却水の流量や圧力を調整してもよい。例えば冷却ヘッダーを間引く前の上側冷却装置１４ａの冷却能力が、下側冷却装置１４ｂの冷却能力よりも上回っている場合、上側冷却装置１４ａを構成する冷却ヘッダーを間引くことが好ましい。 When adjusting the cooling capacity of the upper cooling device 14a and the cooling capacity of the lower cooling device 14b, for example, the cooling header connected to the cooling port 31 of the upper cooling device 14a and the cooling port 31 of the lower cooling device 14b. Each of the cooling headers connected to may be controlled on and off. Or you may control the cooling capacity of each cooling header in the upper side cooling device 14a and the lower side cooling device 14b. That is, you may adjust at least one of the water quantity density of the cooling water injected from each cooling port 31, a pressure, and water temperature.
In addition, the cooling headers (cooling ports 31) of the upper cooling device 14a and the lower cooling device 14b may be thinned out to adjust the flow rate and pressure of the cooling water injected from the upper cooling device 14a and the lower cooling device 14b. . For example, when the cooling capacity of the upper cooling device 14a before thinning out the cooling header is higher than the cooling capacity of the lower cooling device 14b, it is preferable to thin out the cooling header constituting the upper cooling device 14a.
　こうして調整された冷却能力で、上側冷却装置１４ａから熱延鋼板Ｈの上面に冷却水を噴射すると共に、下側冷却装置１４ｂから熱延鋼板Ｈの下面に冷却水を噴射することにより、熱延鋼板Ｈが均一に冷却される。 The cooling capacity thus adjusted is used to inject cooling water onto the upper surface of the hot-rolled steel sheet H from the upper cooling device 14a, and to inject cooling water onto the lower surface of the hot-rolled steel plate H from the lower cooling device 14b. The steel plate H is uniformly cooled.
　その後、冷却装置１４によって冷却された熱延鋼板Ｈに対し、温度計４０と形状計４１によって温度と形状をそれぞれ同一点で定点測定を行い、時系列データとして測定する。なお、温度の測定領域は、熱延鋼板Ｈの幅方向の全域を含む。また、形状とは、定点測定で観測される熱延鋼板Ｈの高さ方向の変動量を示す。さらに、形状の測定領域は、温度の測定領域と同様に熱延鋼板Ｈの幅方向の全域を含む。これらのサンプリングされた時間に通板速度を乗じると、温度及び変動速度などの測定結果の時系列データを圧延方向の位置に紐付けすることが可能となる。 Thereafter, the hot-rolled steel sheet H cooled by the cooling device 14 is subjected to fixed point measurement at the same point by the thermometer 40 and the shape meter 41, and measured as time series data. The temperature measurement region includes the entire region in the width direction of the hot-rolled steel sheet H. Further, the shape indicates the amount of fluctuation in the height direction of the hot-rolled steel sheet H observed by fixed point measurement. Furthermore, the shape measurement region includes the entire region in the width direction of the hot-rolled steel sheet H, similarly to the temperature measurement region. By multiplying these sampled times by the sheet feeding speed, it becomes possible to link time-series data of measurement results such as temperature and fluctuation speed to the position in the rolling direction.
　図４、図５、図６及び図７を使って説明したように、熱延鋼板Ｈの定点での変動速度が正の領域で、定点での平均温度に対して熱延鋼板Ｈの定点での温度が低い場合には、上側冷却能力（上面冷却抜熱量）を小さくすることにより、温度標準偏差を低減することができる。同様に、下側冷却能力（下面冷却抜熱量）を大きくすることにより、温度標準偏差を低減することができる。この関係を利用すれば、温度標準偏差を低減させるために、冷却装置１４の上側冷却装置１４ａと下側冷却装置１４ｂのどちらの冷却能力を調整すればよいのかが明確になる。 As described with reference to FIGS. 4, 5, 6, and 7, the fluctuation rate at the fixed point of the hot-rolled steel sheet H is a positive region, and the fixed temperature of the hot-rolled steel sheet H with respect to the average temperature at the fixed point. When the temperature is low, the temperature standard deviation can be reduced by decreasing the upper cooling capacity (upper surface cooling heat removal amount). Similarly, the temperature standard deviation can be reduced by increasing the lower cooling capacity (lower surface cooling heat removal amount). If this relationship is utilized, in order to reduce the temperature standard deviation, it becomes clear which of the upper cooling device 14a and the lower cooling device 14b of the cooling device 14 should be adjusted.
　すなわち、これらの熱延鋼板Ｈの波形状と紐付けられる温度の変動位置を把握すれば、現在発生している温度標準偏差が上側冷却あるいは下側冷却のどちらによって発生しているのかを明らかにすることが可能となる。したがって、温度標準偏差を小さくするための上側冷却能力（上面冷却抜熱量）と下側冷却能力（下面冷却抜熱量）の増減方向（制御方向）が決定され、上下熱伝達係数比率を調整することができる。
また、温度標準偏差の大きさに基づいて、その温度標準偏差が許容範囲、例えば最小値から最小値＋１０℃以内の範囲に収まるように上下熱伝達係数比率を決定することができる。なお、この温度標準偏差を最小値から最小値＋１０℃以内の範囲に収めることにより、降伏応力、引張強さなどのバラつきを製造許容範囲内に抑えられ、熱延鋼板Ｈを均一に冷却できる。また、かなりのばらつきはあるものの、冷却水量密度比率が、温度標準偏差が最小値となる冷却水量密度比率に対して±５％以内であれば、温度標準偏差が最小値から最小値＋１０℃以内の範囲に収まる。すなわち、冷却水量密度を用いる場合、冷却水量密度の上下比率（冷却水量密度比率）を、温度標準偏差が最小値となる冷却水量密度比率に対して±５％以内に設定することが望ましい。ただし、この許容範囲は必ずしも上下同水量密度を含むとは限らない。 That is, by grasping the temperature fluctuation position associated with the wave shape of these hot-rolled steel sheets H, it is clear whether the temperature standard deviation currently generated is generated by the upper cooling or the lower cooling. It becomes possible to do. Therefore, the increase / decrease direction (control direction) of the upper cooling capacity (upper surface cooling heat removal amount) and lower cooling capacity (lower surface cooling heat removal amount) to reduce the temperature standard deviation is determined, and the vertical heat transfer coefficient ratio is adjusted. Can do.
Further, based on the magnitude of the temperature standard deviation, the upper and lower heat transfer coefficient ratio can be determined so that the temperature standard deviation falls within an allowable range, for example, a range from the minimum value to the minimum value + 10 ° C. In addition, by keeping this temperature standard deviation within the range from the minimum value to the minimum value + 10 ° C., variations in yield stress, tensile strength, and the like can be suppressed within manufacturing tolerances, and the hot-rolled steel sheet H can be cooled uniformly. In addition, although there is considerable variation, if the cooling water volume density ratio is within ± 5% of the cooling water volume density ratio at which the temperature standard deviation is the minimum value, the temperature standard deviation is within the minimum value + 10 ° C from the minimum value. Within the range of. That is, when using the cooling water amount density, it is desirable to set the vertical ratio of the cooling water amount density (cooling water amount density ratio) within ± 5% with respect to the cooling water amount density ratio at which the temperature standard deviation is the minimum value. However, this allowable range does not necessarily include the same upper and lower water density.
　以上の実施形態によれば、予め上側冷却装置１４ａと下側冷却装置１４ｂの冷却能力を調整して、熱延鋼板Ｈを冷却した後、さらに冷却された熱延鋼板Ｈの温度と波形状の測定結果に基づいて、上側冷却装置１４ａの冷却能力と下側冷却装置１４ｂの冷却能力を調整している。このように上側冷却装置１４ａと下側冷却装置１４ｂの冷却能力をフィードバック制御して定性的及び定量的に適切な冷却能力に調整できるので、その後冷却される熱延鋼板Ｈの均一性をより向上させることができる。 According to the above embodiment, after adjusting the cooling capacity of the upper cooling device 14a and the lower cooling device 14b in advance to cool the hot-rolled steel sheet H, the temperature and wave shape of the further cooled hot-rolled steel sheet H are changed. Based on the measurement result, the cooling capacity of the upper cooling device 14a and the cooling capacity of the lower cooling device 14b are adjusted. In this way, the cooling capacity of the upper cooling device 14a and the lower cooling device 14b can be feedback-controlled to adjust the cooling capacity to an appropriate cooling capacity qualitatively and quantitatively, so that the uniformity of the hot-rolled steel sheet H that is subsequently cooled is further improved. Can be made.
　以上のように、本実施形態によれば、熱延鋼板Ｈの温度標準偏差を最小にして当該熱延鋼板Ｈを均一に冷却することができる。 As described above, according to this embodiment, the hot-rolled steel sheet H can be uniformly cooled with the temperature standard deviation of the hot-rolled steel sheet H being minimized.
　以上の実施形態では、温度計４０と形状計４１によって熱延鋼板Ｈの温度と形状を同一の測定位置で定点測定していたが、本願発明者らが調べたところ、温度計４０と形状計４１の測定位置が厳密に同一でなくてもよいことが分かった。具体的には、図８に示すように、熱延鋼板Ｈ上における温度計４０の温度測定箇所Ｐ１と形状計４１の形状測定箇所Ｐ２との位置ずれ（距離）Ｌが、５０ｍｍ以内、より好ましくは３０ｍｍ以内であれば、熱延鋼板Ｈの温度と形状を適切に把握できることが分かった。
この温度計４０と形状計４１との測定箇所の位置ずれＬの方向は、図８に示したように熱延鋼板Ｈの通板方向であってもよいし、熱延鋼板Ｈの板幅方向であってもよく、任意の方向である。なお、図８の例においては、温度計４０が形状計４１の上流側に配置されているが、逆に形状計４１が温度計４０の上流側に配置されていてもよい。 In the above embodiment, the temperature and shape of the hot-rolled steel sheet H were measured at the same measurement position by the thermometer 40 and the shape meter 41. However, when the inventors of the present application examined, the thermometer 40 and the shape meter were measured. It has been found that the measurement positions of 41 need not be exactly the same. Specifically, as shown in FIG. 8, the displacement (distance) L between the temperature measurement point P1 of the thermometer 40 and the shape measurement point P2 of the shape meter 41 on the hot-rolled steel sheet H is more preferably within 50 mm. It was found that the temperature and shape of the hot-rolled steel sheet H can be properly grasped within 30 mm.
The direction of the positional deviation L between the measurement points of the thermometer 40 and the shape meter 41 may be the sheet passing direction of the hot-rolled steel sheet H as shown in FIG. It may be any direction. In the example of FIG. 8, the thermometer 40 is disposed on the upstream side of the shape meter 41, but conversely, the shape meter 41 may be disposed on the upstream side of the thermometer 40.
　ここで、上記温度計４０と形状計４１との測定箇所の位置ずれＬを５０ｍｍ以内とすることが好ましい理由について説明する。表２は、本発明を実機に適用する際に、同一の上下熱伝達係数比率、急峻度、通板速度の条件下において、温度計４０と形状計４１との測定箇所の位置ずれＬを、圧延方向に対して、－２００～＋２００ｍｍの範囲で変化させた場合の、熱延鋼板Ｈの温度標準偏差と、各温度標準偏差と最小値（表２では最小値＝１０．０）との差分（最小値からの標準偏差の差分）との関係を示している。
　なお、表２では、温度計４０の温度測定箇所Ｐ１を基準として、その下流側に形状計４１の形状測定箇所Ｐ２が設定されている場合の位置ずれＬを正の値で示し、その上流側に形状計４１の形状測定箇所Ｐ２が設定されている場合の位置ずれＬを負の値で示している。また、温度計４０の温度測定箇所Ｐ１と形状計４１の形状測定箇所Ｐ２とが同一に設定された場合に、位置ずれＬがゼロとなる。
この表２に示すように、温度計４０と形状計４１との測定箇所の位置ズレＬが、正負に関わらず５０ｍｍ以内であれば、最小値からの標準偏差の差分を＋１０℃以下に低減できることがわかる。 Here, the reason why it is preferable to set the positional deviation L between the measurement points of the thermometer 40 and the shape meter 41 within 50 mm will be described. Table 2 shows the positional deviation L between the measurement points of the thermometer 40 and the shape meter 41 under the conditions of the same vertical heat transfer coefficient ratio, steepness, and plate passing speed when the present invention is applied to an actual machine. The temperature standard deviation of the hot-rolled steel sheet H and the difference between each temperature standard deviation and the minimum value (minimum value = 10.0 in Table 2) when changed in the range of −200 to +200 mm with respect to the rolling direction. It shows the relationship with (difference of standard deviation from minimum value).
In Table 2, with reference to the temperature measurement point P1 of the thermometer 40, the positional deviation L when the shape measurement point P2 of the shape meter 41 is set on the downstream side is shown as a positive value. The position deviation L when the shape measuring point P2 of the shape meter 41 is set is indicated by a negative value. Further, when the temperature measurement point P1 of the thermometer 40 and the shape measurement point P2 of the shape meter 41 are set to be the same, the positional deviation L becomes zero.
As shown in Table 2, the difference in the standard deviation from the minimum value can be reduced to + 10 ° C. or less as long as the positional deviation L between the measurement points of the thermometer 40 and the shape meter 41 is within 50 mm regardless of positive or negative. I understand.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　したがって、温度計４０と形状計４１との測定箇所の位置ずれＬが５０ｍｍ以内であれば、上記実施形態と同様に、温度標準偏差を小さくするための上側冷却能力と下側冷却能力の増減方向（制御方向）を決定することができ、上側冷却装置１４ａと下側冷却装置１４ｂの冷却能力のフィードバック制御を行うことができる。 Therefore, if the positional deviation L between the measurement points of the thermometer 40 and the shape meter 41 is within 50 mm, the increase and decrease directions of the upper cooling capacity and the lower cooling capacity for reducing the temperature standard deviation are the same as in the above embodiment. (Control direction) can be determined, and feedback control of the cooling capacity of the upper cooling device 14a and the lower cooling device 14b can be performed.
　以上の実施形態において、図９に示すように、熱延鋼板Ｈが冷却される冷却区間を圧延方向に複数、例えば２つの分割冷却区間Ｚ１、Ｚ２に分割してもよい。各分割冷却区間Ｚ１、Ｚ２には、それぞれ冷却装置１４が設けられている。また、各分割冷却区間Ｚ１、Ｚ２の境、すなわち分割冷却区間Ｚ１、Ｚ２の下流側には、温度計４０と形状計４１がそれぞれ設けられている。なお、本実施形態では、冷却区間を２つの分割冷却区間に分割したが、分割数はこれに限定されず任意に設定できる。例えば冷却区間を、１つ～５つの分割冷却区間に分割してもよい。 In the above embodiment, as shown in FIG. 9, the cooling zone in which the hot-rolled steel sheet H is cooled may be divided into a plurality of, for example, two divided cooling zones Z1 and Z2 in the rolling direction. A cooling device 14 is provided in each of the divided cooling zones Z1 and Z2. In addition, a thermometer 40 and a shape meter 41 are provided at the boundary between the divided cooling zones Z1 and Z2, that is, downstream of the divided cooling zones Z1 and Z2. In the present embodiment, the cooling section is divided into two divided cooling sections, but the number of divisions is not limited to this and can be arbitrarily set. For example, the cooling section may be divided into 1 to 5 divided cooling sections.
　この場合、各温度計４０と各形状計４１によって、分割冷却区間Ｚ１とＺ２の下流側の熱延鋼板Ｈの温度と波形状をそれぞれ測定する。そして、これらの測定結果に基づき、各分割冷却区間Ｚ１、Ｚ２における上側冷却装置１４ａ及び下側冷却装置１４ｂの冷却能力を制御する。このとき、熱延鋼板Ｈの温度標準偏差が許容範囲、例えば上述したように最小値から最小値＋１０℃以内の範囲に収まるように冷却能力が制御される。これにより、各分割冷却区間Ｚ１、Ｚ２における熱延鋼板Ｈの上面冷却抜熱量及び下面冷却抜熱量の少なくとも一方が調整される。 In this case, the temperature and the wave shape of the hot-rolled steel sheet H on the downstream side of the divided cooling zones Z1 and Z2 are measured by the thermometers 40 and the shape meters 41, respectively. And based on these measurement results, the cooling capacity of the upper side cooling device 14a and the lower side cooling device 14b in each division | segmentation cooling zone Z1, Z2 is controlled. At this time, the cooling capacity is controlled so that the temperature standard deviation of the hot-rolled steel sheet H falls within an allowable range, for example, within the range from the minimum value to the minimum value + 10 ° C. as described above. Accordingly, at least one of the upper surface cooling heat removal amount and the lower surface cooling heat removal amount of the hot-rolled steel sheet H in each of the divided cooling zones Z1 and Z2 is adjusted.
　例えば、分割冷却区間Ｚ１においては、その下流側における温度計４０と形状計４１の測定結果に基づいて、上側冷却装置１４ａと下側冷却装置１４ｂの冷却能力がフィードバック制御され、上面冷却抜熱量及び下面冷却抜熱量の少なくとも一方が調整される。
また、分割冷却区間Ｚ２においては、その下流側における温度計４０と形状計４１の測定結果に基づいて、上側冷却装置１４ａと下側冷却装置１４ｂの冷却能力がフィードフォワード制御されてもよいし、或いはフィードバック制御されてもよい。いずれの場合においても、分割冷却区間Ｚ２において、上面冷却抜熱量及び下面冷却抜熱量の少なくとも一方が調整される。 For example, in the divided cooling zone Z1, the cooling capacity of the upper cooling device 14a and the lower cooling device 14b is feedback-controlled based on the measurement results of the thermometer 40 and the shape meter 41 on the downstream side, and the upper surface cooling heat removal amount and At least one of the bottom surface cooling heat removal amount is adjusted.
In the divided cooling zone Z2, the cooling capacity of the upper cooling device 14a and the lower cooling device 14b may be feedforward controlled based on the measurement results of the thermometer 40 and the shape meter 41 on the downstream side, Alternatively, feedback control may be performed. In any case, at least one of the upper surface cooling heat removal amount and the lower surface cooling heat removal amount is adjusted in the divided cooling zone Z2.
　なお、温度計４０と形状計４１の測定結果に基づいて、上側冷却装置１４ａと下側冷却装置１４ｂの冷却能力を制御する方法は、図４～図７を用いて説明した上記実施形態と同様であるので詳細な説明を省略する。 The method for controlling the cooling capacity of the upper cooling device 14a and the lower cooling device 14b based on the measurement results of the thermometer 40 and the shape meter 41 is the same as that in the above embodiment described with reference to FIGS. Therefore, detailed description is omitted.
　この場合、各分割冷却区間Ｚ１、Ｚ２のそれぞれにおいて、熱延鋼板Ｈの上面冷却抜熱量及び下面冷却抜熱量の少なくとも一方が調整されるので、より細やかな制御が可能となる。したがって、熱延鋼板Ｈをより均一に冷却することができる。 In this case, since at least one of the upper surface cooling heat removal amount and the lower surface cooling heat removal amount of the hot-rolled steel sheet H is adjusted in each of the divided cooling zones Z1 and Z2, finer control is possible. Therefore, the hot-rolled steel sheet H can be cooled more uniformly.
　以上の実施形態において、各分割冷却区間Ｚ１、Ｚ２のそれぞれにおいて、熱延鋼板Ｈの上面冷却抜熱量及び下面冷却抜熱量の少なくとも一方を調整する時に、温度計４０と形状計４１の測定結果に加えて、熱延鋼板Ｈの波形状の急峻度と熱延鋼板Ｈの通板速度の少なくとも一方を用いてもよい。例えばコイル毎に、熱延鋼板Ｈの急峻度や通板速度が一定でない場合もあるため、これら急峻度や通板速度も考慮する。 In the above embodiment, when adjusting at least one of the upper surface cooling heat removal amount and the lower surface cooling heat removal amount of the hot-rolled steel sheet H in each of the divided cooling zones Z1 and Z2, the measurement results of the thermometer 40 and the shape meter 41 are used. In addition, at least one of the wave shape steepness of the hot-rolled steel sheet H and the sheet passing speed of the hot-rolled steel sheet H may be used. For example, since the steepness and the sheet passing speed of the hot-rolled steel sheet H may not be constant for each coil, the steepness and the sheet passing speed are also taken into consideration.
　本願発明者らが調べたところ、例えば図１０に示すように熱延鋼板Ｈの波形状の急峻度が大きくなれば、熱延鋼板Ｈの温度標準偏差が大きくなる。また、例えば図１１に示すように熱延鋼板Ｈの通板速度が高速になると、熱延鋼板Ｈの温度標準偏差が大きくなる。 As a result of investigation by the inventors of the present application, for example, as shown in FIG. 10, when the steepness of the wave shape of the hot-rolled steel sheet H increases, the temperature standard deviation of the hot-rolled steel sheet H increases. For example, as shown in FIG. 11, when the sheet passing speed of the hot-rolled steel sheet H becomes high, the temperature standard deviation of the hot-rolled steel sheet H increases.
　このように熱延鋼板Ｈの急峻度や通板速度が一定でない場合、上下熱伝達係数比率に対する温度標準偏差の変化を定性的に評価できるものの、定量的に正確に評価することができない。そこで、例えば熱延鋼板Ｈの急峻度や通板速度に応じた温度標準偏差を予め求めておき、熱延鋼板Ｈの少なくとも急峻度又は通板速度を測定して、温度標準偏差を補正する。そして、この補正された温度標準偏差に基づいて、各分割冷却区間Ｚ１、Ｚ２における熱延鋼板Ｈの上面冷却抜熱量及び下面冷却抜熱量を補正する。これにより、熱延鋼板Ｈをさらに均一に冷却することができる。 Thus, when the steepness of the hot-rolled steel sheet H and the sheet passing speed are not constant, the change of the temperature standard deviation with respect to the ratio of the vertical heat transfer coefficient can be qualitatively evaluated but cannot be quantitatively and accurately evaluated. Therefore, for example, a temperature standard deviation corresponding to the steepness or sheet passing speed of the hot-rolled steel sheet H is obtained in advance, and at least the steepness or sheet passing speed of the hot-rolled steel sheet H is measured to correct the temperature standard deviation. And based on this correct | amended temperature standard deviation, the upper surface cooling heat removal amount and lower surface cooling heat removal amount of the hot-rolled steel sheet H in each division | segmentation cooling zone Z1, Z2 are correct | amended. Thereby, the hot-rolled steel sheet H can be cooled more uniformly.
　また、本実施形態によれば、熱延鋼板Ｈの板幅方向においても均一な形状や材質となるように仕上げることが可能となる。図１２は、中伸びによって板幅方向に異なる振幅が生じている波形状の例を示している。このように、板幅方向に生じる振幅の異なる波形状に起因して温度標準偏差が発生する場合であっても、上述した本実施形態によれば、この板幅方向の温度標準偏差を低減することが可能となる。 Further, according to the present embodiment, it is possible to finish the hot rolled steel sheet H so as to have a uniform shape and material in the sheet width direction. FIG. 12 shows an example of a wave shape in which different amplitudes are generated in the plate width direction due to middle elongation. As described above, even if the temperature standard deviation occurs due to the wave shapes having different amplitudes generated in the plate width direction, the temperature standard deviation in the plate width direction is reduced according to the above-described embodiment. It becomes possible.
　ここで、本願発明者らが鋭意検討した結果、熱延鋼板Ｈの通板速度を、５５０ｍ／ｍｉｎ以上から機械的な限界速度以下の範囲内に設定することにより、熱延鋼板Ｈをより均一にできることが分かった。 Here, as a result of intensive studies by the present inventors, the hot-rolled steel sheet H is made more uniform by setting the sheet-passing speed of the hot-rolled steel sheet H within a range from 550 m / min or more to a mechanical limit speed or less. I understood that I can do it.
　熱延鋼板Ｈの通板速度を５５０ｍ／ｍｉｎ以上に設定すると、熱延鋼板Ｈに冷却水を噴射しても、熱延鋼板Ｈ上の乗り水の影響が顕著に少なくなることが分かった。このため、乗り水による熱延鋼板Ｈの不均一冷却も回避することができる。 It has been found that when the sheet passing speed of the hot-rolled steel sheet H is set to 550 m / min or more, even if the cooling water is injected onto the hot-rolled steel sheet H, the influence of the water on the hot-rolled steel sheet H is remarkably reduced. For this reason, the non-uniform cooling of the hot-rolled steel sheet H by the riding water can be avoided.
　図１３は、他の実施形態における熱間圧延設備２の例を模式的に示している。この熱間圧延設備２は、加熱したスラブＳをロールで上下に挟んで連続的に圧延し、最小１．２ｍｍまで薄くしてこれを巻き取ることを目的とした設備である。
この熱間圧延設備２は、スラブＳを加熱するための加熱炉１１１と、この加熱炉１１１において加熱されたスラブＳを幅方向に圧延する幅方向圧延機１１６と、この幅方向に圧延されたスラブＳを上下方向から圧延して粗バーにする粗圧延機１１２と、粗バーをさらに所定の厚みまで連続して熱間仕上圧延をする仕上圧延機１１３と、この仕上圧延機１１３により熱間仕上圧延された熱延鋼板Ｈを冷却水により冷却する冷却装置１１４と、冷却装置１１４により冷却された熱延鋼板Ｈをコイル状に巻き取る巻取装置１１５とを備えている。 FIG. 13 schematically shows an example of the hot rolling facility 2 in another embodiment. This hot rolling facility 2 is a facility intended to continuously roll a heated slab S sandwiched between rolls and to roll it down to a minimum thickness of 1.2 mm.
This hot rolling facility 2 is rolled in the width direction, a heating furnace 111 for heating the slab S, a width-direction rolling mill 116 that rolls the slab S heated in the heating furnace 111 in the width direction, and the width direction. A roughing mill 112 that rolls the slab S from above and below to form a rough bar, a finishing mill 113 that continuously hot-rolls the rough bar to a predetermined thickness, and a hot rolling by the finishing mill 113. A cooling device 114 that cools the hot-rolled steel sheet H that has been finish-rolled with cooling water, and a winding device 115 that winds the hot-rolled steel plate H cooled by the cooling device 114 into a coil shape.
　加熱炉１１１には、装入口を介して外部から搬入されてきたスラブＳに対して、火炎を吹き出すことによりスラブＳを加熱するサイドバーナ、軸流バーナ、ルーフバーナが配設されている。加熱炉１１１に搬入されたスラブＳは、各ゾーンにおいて形成される各加熱帯において順次加熱され、さらに最終ゾーンにおいて形成される均熱帯において、ルーフバーナを利用してスラブＳを均等加熱することにより、最適温度で搬送できるようにするための保熱処理を行う。加熱炉１１１における加熱処理が全て終了すると、スラブＳは加熱炉１１１外へと搬送され、粗圧延機１１２による圧延工程へと移行することになる。 The heating furnace 111 is provided with a side burner, an axial flow burner, and a roof burner for heating the slab S by blowing out flames with respect to the slab S carried in from the outside through the loading port. The slab S carried into the heating furnace 111 is sequentially heated in each heating zone formed in each zone, and further, in the soaking zone formed in the final zone, by heating the slab S evenly using a roof burner, A coercive heat treatment is performed to enable conveyance at the optimum temperature. When all the heat treatments in the heating furnace 111 are completed, the slab S is transferred to the outside of the heating furnace 111 and moves to a rolling process by the rough rolling mill 112.
　粗圧延機１１２において、加熱炉１１１から搬送されてきたスラブＳは、複数スタンドに亘って配設される円柱状の回転ロールの間隙を通過する。例えば、この粗圧延機１１２は、第１スタンドにおいて上下に配設されたワークロール１１２ａのみによりスラブＳを熱間圧延して粗バーとする。
次に、このワークロール１１２ａを通過した粗バーをワークロールとバックアップロールとで構成される複数の４重圧延機１１２ｂにより、さらに連続的に圧延する。その結果、この粗圧延工程の終了時に、粗バーは、厚さ３０～６０ｍｍ程度まで圧延され、仕上圧延機１１３へと搬送されることになる。なお、粗圧延機１１２の構成は本実施形態に記載したものに限定されず、ロール数等は任意に設定することが可能である。 In the rough rolling mill 112, the slab S conveyed from the heating furnace 111 passes through a gap between cylindrical rotary rolls arranged over a plurality of stands. For example, the rough rolling mill 112 hot-rolls the slab S with only the work rolls 112a disposed up and down in the first stand to form a rough bar.
Next, the coarse bar that has passed through the work roll 112a is further continuously rolled by a plurality of quadruple rolling mills 112b each composed of a work roll and a backup roll. As a result, at the end of the rough rolling step, the rough bar is rolled to a thickness of about 30 to 60 mm and conveyed to the finishing mill 113. In addition, the structure of the rough rolling mill 112 is not limited to what was described in this embodiment, The number of rolls etc. can be set arbitrarily.
仕上圧延機１１３は、粗圧延機１１２から搬送されてきた粗バーを、その厚さが数ｍｍ程度になるまで仕上げ圧延する。これら仕上圧延機１１３は、６～７スタンドに亘って上下一直線に並べた仕上げ圧延ロール１１３ａの間隙に粗バーを通過させ、これを徐々に圧下していく。この仕上圧延機１１３により仕上げ圧延された熱延鋼板Ｈは、搬送ロール１３２（図１４参照）によって冷却装置１１４へ搬送される。なお、上述した上下一直線に並べた一対の仕上げ圧延ロール１１３ａを備えた圧延機は、いわゆる圧延スタンドとも呼称される。 The finish rolling mill 113 finish-rolls the rough bar conveyed from the rough rolling mill 112 until the thickness becomes about several mm. These finish rolling mills 113 allow the coarse bars to pass through the gaps between the finish rolling rolls 113a arranged in a straight line over 6 to 7 stands, and gradually reduce them. The hot-rolled steel sheet H finish-rolled by the finish rolling mill 113 is transported to the cooling device 114 by a transport roll 132 (see FIG. 14). In addition, the rolling mill provided with the above-described pair of finish rolling rolls 113a arranged in a straight line is also referred to as a so-called rolling stand.
また、６～７スタンドに亘って並べられた各圧延ロール１１３ａの間（すなわち、圧延スタンド間）には、仕上げ圧延中におけるスタンド間冷却（補助冷却）を行う冷却装置１４２（補助冷却装置）が配置されている。この冷却装置１４２の装置構成等の詳細な説明については、図１７を参照して後述する。なお、図１３には、仕上圧延機１１３における２箇所に冷却装置１４２が配置されている場合を図示しているが、この冷却装置１４２は全ての圧延ロール１１３ａ間に設けられてもよく、一部にのみ設けられる構成でも良い。 Further, a cooling device 142 (auxiliary cooling device) that performs cooling between the stands (auxiliary cooling) during finish rolling is provided between the rolling rolls 113a arranged over 6 to 7 stands (that is, between the rolling stands). Has been placed. A detailed description of the configuration of the cooling device 142 will be described later with reference to FIG. FIG. 13 shows a case where the cooling devices 142 are arranged at two locations in the finishing mill 113, but this cooling device 142 may be provided between all the rolling rolls 113a. The structure provided only in a part may be sufficient.
　冷却装置１１４は、仕上圧延機１１３から搬送される熱延鋼板Ｈに対してラミナーやスプレーによるノズル冷却を施すための設備である。この冷却装置１１４は、図１４に示すように、ランナウトテーブルの搬送ロール１３２上を移動する熱延鋼板Ｈの上面に対して、上側の冷却口１３１から冷却水を噴射する上側冷却装置１１４ａと、熱延鋼板Ｈの下面に対して、下側の冷却口１３１から冷却水を噴射する下側冷却装置１１４ｂとを備えている。
冷却口１３１は、上側冷却装置１１４ａ及び下側冷却装置１１４ｂのそれぞれについて複数個設けられている。また、冷却口１３１には、冷却ヘッダー（図示省略）が接続されている。この冷却口１３１の個数によって、上側冷却装置１１４ａ及び下側冷却装置１１４ｂの冷却能力が決定される。なお、この冷却装置１１４は、上下スプリットラミナー、パイプラミナー、スプレー冷却等の少なくとも一つで構成されていてもよい。 The cooling device 114 is a facility for cooling the hot-rolled steel sheet H conveyed from the finish rolling mill 113 by nozzle laminator or spray. As shown in FIG. 14, the cooling device 114 has an upper cooling device 114a for injecting cooling water from the upper cooling port 131 to the upper surface of the hot-rolled steel sheet H moving on the transport roll 132 of the run-out table, On the lower surface of the hot-rolled steel sheet H, a lower cooling device 114b for injecting cooling water from the lower cooling port 131 is provided.
A plurality of cooling ports 131 are provided for each of the upper cooling device 114a and the lower cooling device 114b. A cooling header (not shown) is connected to the cooling port 131. The cooling capacity of the upper cooling device 114a and the lower cooling device 114b is determined by the number of the cooling ports 131. The cooling device 114 may be composed of at least one of upper and lower split laminar, pipe laminar, spray cooling, and the like.
　この冷却装置１１４において、上側冷却装置１１４ａの冷却能力と下側冷却装置１１４ｂの冷却能力を調整する際には、例えば上側冷却装置１１４ａの冷却口１３１に接続される冷却ヘッダーと下側冷却装置１１４ｂの冷却口１３１に接続される冷却ヘッダーとを、それぞれオンオフ制御してもよい。
あるいは、上側冷却装置１１４ａと下側冷却装置１１４ｂにおける各冷却ヘッダーの操業パラメータを制御してもよい。即ち、各冷却口１３１から噴出される冷却水の水量密度、圧力、水温の少なくとも一つを調整してもよい。
また、上側冷却装置１１４ａと下側冷却装置１１４ｂの冷却ヘッダー（冷却口１３１）を間引いて、上側冷却装置１１４ａと下側冷却装置１１４ｂから噴射される冷却水の流量や圧力を調整してもよい。例えば、冷却ヘッダーを間引く前における上側冷却装置１１４ａの冷却能力が、下側冷却装置１１４ｂの冷却能力よりも上回っている場合、上側冷却装置１１４ａを構成する冷却ヘッダーを間引くことが好ましい。 In this cooling device 114, when adjusting the cooling capacity of the upper cooling device 114a and the cooling capacity of the lower cooling device 114b, for example, the cooling header connected to the cooling port 131 of the upper cooling device 114a and the lower cooling device 114b The cooling headers connected to the cooling ports 131 may be on / off controlled respectively.
Or you may control the operation parameter of each cooling header in the upper side cooling device 114a and the lower side cooling device 114b. That is, at least one of the water density, pressure, and water temperature of the cooling water ejected from each cooling port 131 may be adjusted.
Further, the cooling headers (cooling ports 131) of the upper cooling device 114a and the lower cooling device 114b may be thinned out to adjust the flow rate and pressure of the cooling water injected from the upper cooling device 114a and the lower cooling device 114b. . For example, when the cooling capacity of the upper cooling device 114a before thinning out the cooling header is higher than the cooling capacity of the lower cooling device 114b, it is preferable to thin out the cooling header constituting the upper cooling device 114a.
　巻取装置１１５は、図１３に示すように、冷却装置１１４により冷却された熱延鋼板Ｈを所定の巻取温度で巻き取る。巻取装置１１５によりコイル状に巻き取られた熱延鋼板Ｈは、熱間圧延設備２外へと搬送されることになる。 As shown in FIG. 13, the winding device 115 winds the hot-rolled steel sheet H cooled by the cooling device 114 at a predetermined winding temperature. The hot-rolled steel sheet H wound in a coil shape by the winding device 115 is transported outside the hot rolling facility 2.
　以上のように構成された熱間圧延設備２の冷却装置１１４において、圧延方向に表面高さ（波高さ）が変動する波形状が形成されている熱延鋼板Ｈの冷却が行われる場合に、上述したように、上側冷却装置１１４ａから噴射される冷却水と、下側冷却装置１１４ｂから噴射される冷却水の水量密度、圧力、水温等を適切に調整することで熱延鋼板Ｈを均一に冷却することができる。しかしながら、特に熱延鋼板Ｈの通板速度が遅い場合には、熱延鋼板Ｈと搬送ロール１３２やエプロン１３３とが局所的に接触する時間が長くなり、熱延鋼板Ｈの搬送ロール１３２やエプロン１３３との接触部分が接触抜熱により冷却され易くなることから、冷却が不均一となってしまう。この冷却の不均一性の要因について以下に図面を参照して説明する。 In the cooling device 114 of the hot rolling facility 2 configured as described above, when the hot-rolled steel sheet H in which a corrugated shape whose surface height (wave height) fluctuates in the rolling direction is formed is performed, As described above, the hot-rolled steel sheet H is made uniform by appropriately adjusting the water density, pressure, water temperature, etc. of the cooling water injected from the upper cooling device 114a and the cooling water injected from the lower cooling device 114b. Can be cooled. However, especially when the sheet passing speed of the hot-rolled steel sheet H is slow, the time for which the hot-rolled steel sheet H and the transport roll 132 and the apron 133 are in contact with each other is long, and the transport roll 132 and apron of the hot-rolled steel sheet H are increased. Since the contact portion with 133 is easily cooled by contact heat removal, the cooling becomes uneven. The cause of this non-uniform cooling will be described below with reference to the drawings.
　図１５Ａに示すように、熱延鋼板Ｈがその圧延方向に波形状を有する場合、この熱延鋼板Ｈの波形状の底部が、搬送ロール１３２と局所的に接触する可能性がある。また、図１５Ｂに示すように、圧延方向に沿って隣り合う搬送ロール１３２同士の間に、熱延鋼板Ｈが落ち込むのを防止するためのサポートとしてエプロン１３３が設けられている場合がある。この場合、熱延鋼板Ｈの波形状の底部が、搬送ロール１３２及びエプロン１３３と局所的に接触する可能性がある。このように、熱延鋼板Ｈにおいて、搬送ロール１３２やエプロン１３３と局所的に接触する部分は、接触抜熱によって他の部分よりも冷却され易くなる。このため、熱延鋼板Ｈが不均一に冷却される。 As shown in FIG. 15A, when the hot-rolled steel sheet H has a corrugated shape in the rolling direction, the corrugated bottom of the hot-rolled steel sheet H may locally contact the transport roll 132. Moreover, as shown to FIG. 15B, the apron 133 may be provided as a support for preventing that the hot-rolled steel plate H falls between the conveyance rolls 132 adjacent along a rolling direction. In this case, there is a possibility that the corrugated bottom portion of the hot-rolled steel sheet H locally contacts the transport roll 132 and the apron 133. As described above, in the hot-rolled steel sheet H, the part that locally contacts the transport roll 132 and the apron 133 is more easily cooled than the other part due to contact heat removal. For this reason, the hot-rolled steel sheet H is cooled unevenly.
　特に、熱延鋼板Ｈの通板速度が低速の場合、その熱延鋼板Ｈが搬送ロール１３２やエプロン１３３と局所的に接触する時間が長くなる。その結果、図１６Ａに示すように、熱延鋼板Ｈが搬送ロール１３２やエプロン１３３と局所的に接触する部分（図１６Ａ中の点線で囲った部分）が他の部分より冷却され易くなり、熱延鋼板Ｈが不均一に冷却される。
一方、熱延鋼板Ｈの通板速度を高速にすると、上記接触時間が短くなる。しかも、通板速度が高速化すると、熱延鋼板Ｈと搬送ロール１３２やエプロン１３３との接触による反発によって、通板中の熱延鋼板Ｈが、これら搬送ロール１３２やエプロン１３３から浮いた状態になる。
また、熱延鋼板Ｈの通板速度を高速化すると、上記接触による反発によって熱延鋼板Ｈが搬送ロール１３２やエプロン１３３から浮いた状態となることに加え、熱延鋼板Ｈと搬送ロール１３２やエプロン１３３との接触時間や接触回数が減少するため、その接触による温度降下は無視できるほどに小さくなる。
従って、通板速度を高速化することで接触抜熱を抑制することができ、図１６Ｂに示すように、熱延鋼板Ｈをより均一に冷却することができる。そして、前述した上下面抜熱量制御に加えて、この通板速度を５５０ｍ／ｍｉｎ以上に設定することにより、熱延鋼板Ｈを十分に均一に冷却できることを発明者らは見出した。
なお、このような知見は、波形状が形成された熱延鋼板Ｈにおける冷却について得られたものであるが、その波形状の高さに拘らず、熱延鋼板Ｈの最下点は、搬送ロール１３２やエプロン１３３と接触することになるため、波形状の高さに依らずに通板速度を高速化することは、均一な冷却を行うのに有効である。 In particular, when the sheet passing speed of the hot-rolled steel sheet H is low, the time during which the hot-rolled steel sheet H locally contacts the transport roll 132 and the apron 133 becomes longer. As a result, as shown in FIG. 16A, the portion where the hot-rolled steel sheet H is locally in contact with the transport roll 132 and the apron 133 (portion surrounded by the dotted line in FIG. 16A) is more easily cooled than the other portions. The rolled steel sheet H is cooled unevenly.
On the other hand, when the sheet passing speed of the hot-rolled steel sheet H is increased, the contact time is shortened. In addition, when the sheet passing speed is increased, the hot rolled sheet steel H in the sheet passing plate is lifted from the sheet conveying roll 132 and the apron 133 due to repulsion due to contact between the hot rolled sheet steel H and the conveying roll 132 and the apron 133. Become.
Further, when the sheet passing speed of the hot-rolled steel sheet H is increased, the hot-rolled steel sheet H is lifted from the transport roll 132 and the apron 133 due to the repulsion due to the contact, and the hot-rolled steel sheet H and the transport roll 132 Since the contact time and the number of times of contact with the apron 133 are reduced, the temperature drop due to the contact becomes negligibly small.
Therefore, contact heat removal can be suppressed by increasing the sheet passing speed, and the hot-rolled steel sheet H can be cooled more uniformly as shown in FIG. 16B. The inventors have found that the hot-rolled steel sheet H can be cooled sufficiently uniformly by setting the sheet passing speed to 550 m / min or more in addition to the above-described heat removal control on the upper and lower surfaces.
In addition, although such knowledge is obtained about the cooling in the hot-rolled steel sheet H in which the corrugated shape was formed, the lowest point of the hot-rolled steel sheet H is conveyed regardless of the height of the corrugated shape. Since it comes in contact with the roll 132 and the apron 133, increasing the sheet passing speed regardless of the height of the wave shape is effective for uniform cooling.
　また、熱延鋼板Ｈの通板速度を５５０ｍ／ｍｉｎ以上に設定すると、熱延鋼板Ｈが、搬送ロール１３２やエプロン１３３から浮いた状態になるため、この状態で熱延鋼板Ｈに冷却水を噴射しても、従来のように熱延鋼板Ｈ上には乗り水が存在しない。従って、乗り水が原因で熱延鋼板Ｈが不均一に冷却されることを回避することができる。 Moreover, since the hot-rolled steel sheet H will be in the state which floated from the conveyance roll 132 or the apron 133 if the plate-feeding speed of the hot-rolled steel sheet H is set to 550 m / min or more, cooling water is supplied to the hot-rolled steel sheet H in this state. Even if it injects, there is no boarding water on the hot-rolled steel sheet H as in the prior art. Therefore, it is possible to avoid the hot-rolled steel sheet H from being unevenly cooled due to the riding water.
　以上のように、冷却区間における熱延鋼板Ｈの通板速度を５５０ｍ／ｍｉｎ以上に設定すれば、圧延方向に周期的に波高さが変動する波形状を有する熱延鋼板Ｈをより均一に冷却できる。
　なお、熱延鋼板Ｈの通板速度は、高速であるほど良いが、機械的な限界速度（例えば、１５５０ｍ／ｍｉｎ）を越えることは不可能である。従って、実質的に、冷却区間における熱延鋼板Ｈの通板速度は、５５０ｍ／ｍｉｎ以上から機械的な限界速度以下までの範囲内に設定されることになる。また、実操業時における通板速度の上限値（操業上限速度）が予め定められている場合には、熱延鋼板Ｈの通板速度を、５５０ｍ／ｍｉｎ以上から操業上限速度（例えば、１２００ｍ／ｍｉｎ）以下までの範囲内に設定することが好ましい。
　勿論、図３を用いて説明した熱延鋼板冷却装置を熱間圧延設備２に適用して、熱延鋼板Ｈの上面冷却抜熱量及び下面冷却抜熱量の制御と、通板速度の高速度設定（５５０ｍ／ｍｉｎ以上から機械的な限界速度以下までの範囲内に設定）とを組み合わせても良い。 As described above, when the sheet passing speed of the hot-rolled steel sheet H in the cooling section is set to 550 m / min or more, the hot-rolled steel sheet H having a wave shape whose wave height periodically varies in the rolling direction is more uniformly cooled. it can.
In addition, although the plate-passing speed of the hot-rolled steel sheet H is better as it is higher, it is impossible to exceed the mechanical limit speed (for example, 1550 m / min). Therefore, the sheet feeding speed of the hot-rolled steel sheet H in the cooling section is substantially set within a range from 550 m / min or more to a mechanical limit speed or less. Moreover, when the upper limit (operation upper limit speed) of the sheeting speed at the time of an actual operation is predetermined, the operation upper limit speed (for example, 1200 m / min) is set from 550 m / min or more. min) is preferably set within a range up to or below.
Of course, the hot-rolled steel sheet cooling device described with reference to FIG. 3 is applied to the hot rolling facility 2 to control the upper surface cooling heat removal amount and the lower surface cooling heat removal amount of the hot-rolled steel sheet H, and to set a high plate feed speed. (Set within a range from 550 m / min or more to a mechanical limit speed or less) may be combined.
　また、一般的に、引張強度が大きい熱延鋼板Ｈ（特に、引張強度（ＴＳ）が８００ＭＰａ以上であって、現実的には１４００ＭＰａを上限とする、いわゆるハイテンと呼ばれる鋼板など）である場合には、その熱延鋼板Ｈの硬度が高いことに起因して、熱間圧延設備２における圧延時に生じる加工発熱が大きくなることが知られている。従って、従来は、冷却装置１１４（つまり冷却区間）における熱延鋼板Ｈの通板速度を低く抑えることにより、冷却を十分に行うものとしていた。 In general, when the steel sheet is a hot-rolled steel sheet H having a high tensile strength (particularly a steel sheet called so-called high tensile steel having a tensile strength (TS) of 800 MPa or more and a practical upper limit of 1400 MPa). It is known that due to the high hardness of the hot-rolled steel sheet H, processing heat generated during rolling in the hot rolling equipment 2 is increased. Therefore, conventionally, cooling is sufficiently performed by suppressing the sheet passing speed of the hot-rolled steel sheet H in the cooling device 114 (that is, the cooling section).
しかしながら、冷却装置１１４における熱延鋼板Ｈの通板速度を低く抑えると、熱延鋼板Ｈに波形状が形成されている場合に、上述したように熱延鋼板Ｈと搬送ロール１３２やエプロン１３３との局所的な接触により、接触部分が接触抜熱により冷却され易くなり、不均一な冷却が行われてしまう。 However, if the sheet passing speed of the hot-rolled steel sheet H in the cooling device 114 is kept low, when the corrugated shape is formed on the hot-rolled steel sheet H, as described above, the hot-rolled steel sheet H, the transport roll 132, the apron 133, Due to the local contact, the contact portion is easily cooled by contact heat removal, and uneven cooling is performed.
そこで、本願発明者らは、熱間圧延設備２の仕上圧延機１１３において、例えば６～７スタンドに亘って設けられる一対の仕上げ圧延ロール１１３ａ（即ち、圧延スタンド）同士の間で、冷却（いわゆるスタンド間冷却）を行うことにより、上記加工発熱を抑制し、冷却装置１１４における熱延鋼板Ｈの通板速度を５５０ｍ／ｍｉｎ以上に設定できることを見出した。以下では、図１７を参照して、上記のスタンド間冷却について説明する。 Therefore, the inventors of the present application, in the finishing mill 113 of the hot rolling facility 2, for example, cooled between a pair of finish rolling rolls 113a (that is, rolling stands) provided over, for example, 6 to 7 stands (so-called rolling stands). It was found that by performing (cooling between stands), the processing heat generation can be suppressed, and the sheet feeding speed of the hot-rolled steel sheet H in the cooling device 114 can be set to 550 m / min or more. Hereinafter, the inter-stand cooling will be described with reference to FIG.
図１７は、スタンド間冷却を行うことが可能な仕上圧延機１１３の説明図であり、説明のため仕上圧延機１１３の一部を拡大し、３つの圧延スタンドについて図示したものである。なお、図１７において、上記実施形態と同一の構成要素については同一の符号を付している。図１７に示すように、仕上げ圧延機１１３には、上下一直線に並べた一対の仕上げ圧延ロール１１３ａ等を備える圧延スタンド１４０が複数（図１７においては３つ）設けられている。各圧延スタンド１４０同士の間には、ラミナーやスプレーによるノズル冷却を施す設備である冷却装置１４２が設けられており、圧延スタンド１４０同士の間において、熱延鋼板Ｈに対してスタンド間冷却を行うことが可能となっている。 FIG. 17 is an explanatory diagram of the finishing mill 113 capable of performing inter-stand cooling. For the sake of explanation, a part of the finishing mill 113 is enlarged to illustrate three rolling stands. In FIG. 17, the same components as those in the above embodiment are given the same reference numerals. As shown in FIG. 17, the finish rolling mill 113 is provided with a plurality of rolling stands 140 (three in FIG. 17) including a pair of finish rolling rolls 113a and the like arranged in a straight line. Between each rolling stand 140, the cooling device 142 which is the equipment which performs nozzle cooling by a laminar or a spray is provided, and inter-stand cooling is performed with respect to the hot-rolled steel sheet H between the rolling stands 140. It is possible.
この冷却装置１４２は、図１７に示すように、仕上げ圧延機１１３において搬送される熱延鋼板Ｈに対して冷却口１４６により上側から冷却水を噴出させる上側冷却装置１４２ａと、熱延鋼板Ｈ下面に対して下側から冷却水を噴出させる下側冷却装置１４２ｂとを備えている。冷却口１４６は、上側冷却装置１４２ａ及び下側冷却装置１４２ｂのそれぞれについて複数個設けられている。また、冷却口１４６には、冷却ヘッダー（図示省略）が接続されている。なお、この冷却装置１４２は、上下スプリットラミナー、パイプラミナー、スプレー冷却等の少なくとも一つで構成されていてもよい。 As shown in FIG. 17, the cooling device 142 includes an upper cooling device 142 a that ejects cooling water from the upper side through a cooling port 146 to the hot rolled steel plate H conveyed in the finish rolling mill 113, and a lower surface of the hot rolled steel plate H. And a lower cooling device 142b for ejecting cooling water from the lower side. A plurality of cooling ports 146 are provided for each of the upper cooling device 142a and the lower cooling device 142b. In addition, a cooling header (not shown) is connected to the cooling port 146. The cooling device 142 may be composed of at least one of upper and lower split laminar, pipe laminar, spray cooling, and the like.
図１７に示す構成を有する仕上げ圧延機１１３において、特に熱延鋼板Ｈの引張強度（ＴＳ）が８００ＭＰａ以上である場合に、スタンド間冷却を行うことで熱延鋼板Ｈの加工発熱が抑制される。これにより、冷却装置１１４における熱延鋼板Ｈの通板速度を５５０ｍ／ｍｉｎ以上に保つことが可能となる。従って、従来の低速な通板速度で冷却を行う場合に問題となっていた、熱延鋼板Ｈと搬送ロール１３２やエプロン１３３との局所的な接触により、接触部分が接触抜熱により冷却され易くなるといった点が解消され、熱延鋼板Ｈを十分に均一に冷却することができる。 In the finish rolling mill 113 having the configuration shown in FIG. 17, particularly when the tensile strength (TS) of the hot-rolled steel sheet H is 800 MPa or more, processing heat generation of the hot-rolled steel sheet H is suppressed by performing inter-stand cooling. . Thereby, it is possible to keep the sheet passing speed of the hot-rolled steel sheet H in the cooling device 114 at 550 m / min or more. Therefore, the contact portion is easily cooled by contact heat removal due to local contact between the hot-rolled steel sheet H and the transport roll 132 or the apron 133, which has been a problem when cooling is performed at a conventional low plate speed. Therefore, the hot-rolled steel sheet H can be cooled sufficiently uniformly.
　以上の実施形態において、冷却装置１１４による熱延鋼板Ｈの冷却は、仕上圧延機出側温度から、その熱延鋼板Ｈの温度が６００℃までの範囲で行われるのが好ましい。熱延鋼板Ｈの温度が６００℃以上の温度領域は、いわゆる膜沸騰領域である。すなわち、この場合、いわゆる遷移沸騰領域を回避し、膜沸騰領域で熱延鋼板Ｈを水冷することができる。遷移沸騰領域では、熱延鋼板Ｈの表面に冷却水を噴射した際、その熱延鋼板Ｈの表面において、蒸気膜に覆われる部分と、冷却水が熱延鋼板Ｈに直接噴射される部分とが混在する。このため、熱延鋼板Ｈを均一に冷却することができない。
一方、膜沸騰領域では、熱延鋼板Ｈの表面全体が蒸気膜に覆われた状態で熱延鋼板Ｈの冷却が行われるので、熱延鋼板Ｈを均一に冷却することができる。したがって、本実施形態のように熱延鋼板Ｈの温度が６００℃以上の範囲において、熱延鋼板Ｈをより均一に冷却することができる。 In the above embodiment, the cooling of the hot-rolled steel sheet H by the cooling device 114 is preferably performed in the range from the finish rolling mill outlet temperature to the temperature of the hot-rolled steel sheet H up to 600 ° C. The temperature region where the temperature of the hot-rolled steel sheet H is 600 ° C. or higher is a so-called film boiling region. That is, in this case, the so-called transition boiling region can be avoided and the hot-rolled steel sheet H can be water-cooled in the film boiling region. In the transition boiling region, when the cooling water is sprayed on the surface of the hot-rolled steel sheet H, the surface covered with the vapor film on the surface of the hot-rolled steel sheet H, the part where the cooling water is directly sprayed on the hot-rolled steel sheet H, Are mixed. For this reason, the hot-rolled steel sheet H cannot be cooled uniformly.
On the other hand, in the film boiling region, since the hot-rolled steel sheet H is cooled in a state where the entire surface of the hot-rolled steel sheet H is covered with the vapor film, the hot-rolled steel sheet H can be uniformly cooled. Therefore, the hot-rolled steel sheet H can be cooled more uniformly in the range where the temperature of the hot-rolled steel sheet H is 600 ° C. or more as in this embodiment.
　以上、添付図面を参照しながら本発明の好適な実施形態について説明したが、本発明は上記実施形態に限定されない。当業者であれば、特許請求の範囲に記載された思想の範疇内において、各種の変更例または修正例に想到し得ることは明らかであり、それらについても当然に本発明の技術的範囲に属するものと了解される。 The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to the above-described embodiments. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the idea described in the claims, and these naturally belong to the technical scope of the present invention. It is understood.
　本願発明者は、熱延鋼板の通板速度を５５０ｍ／ｍｉｎ以上に設定することで、熱延鋼板の冷却が均一に行われることを実証するため、実施例として熱延鋼板の冷却実験を行った。 In order to demonstrate that the hot-rolled steel sheet is uniformly cooled by setting the sheet-passing speed of the hot-rolled steel sheet to 550 m / min or more, the present inventor conducted a cooling experiment on the hot-rolled steel sheet as an example. It was.
（実施例１）
　板厚２．５ｍｍ、幅１２００ｍｍ、引張強度４００ＭＰａ及び急峻度２％の中波が形成された熱延鋼板について、冷却装置での通板速度を変更して冷却を行った。具体的には、通板速度を４００ｍ／ｍｉｎ、４５０ｍ／ｍｉｎ、５００ｍ／ｍｉｎ、５５０ｍ／ｍｉｎ、６００ｍ／ｍｉｎ、６５０ｍ／ｍｉｎに変更し、各通板速度での熱延鋼板の冷却を２０回ずつ行った。
そして、巻き取り時の熱延鋼板の温度を測定し、その温度測定結果を用いて温度変動の標準偏差の平均値（ＣＴ温度変動量）を算出した。その算出されたＣＴ温度変動量について評価を行った結果を以下の表３に示す。なお、評価基準としては、ＣＴ温度変動量が２５℃より大きい場合には、均一に冷却されていないと評価し、ＣＴ温度変動量が２５℃以下の場合には、均一に冷却されていると評価した。 (Example 1)
The hot-rolled steel sheet on which a plate thickness of 2.5 mm, a width of 1200 mm, a tensile strength of 400 MPa, and a steepness of 2% was formed was cooled by changing the sheet passing speed in the cooling device. Specifically, the sheeting speed is changed to 400 m / min, 450 m / min, 500 m / min, 550 m / min, 600 m / min, and 650 m / min, and the hot-rolled steel sheet is cooled 20 times at each sheeting speed. I went one by one.
And the temperature of the hot-rolled steel plate at the time of winding was measured, and the average value (CT temperature fluctuation amount) of the standard deviation of temperature fluctuation was computed using the temperature measurement result. The results of evaluating the calculated CT temperature fluctuation amount are shown in Table 3 below. As an evaluation standard, when the CT temperature fluctuation amount is larger than 25 ° C., it is evaluated that it is not uniformly cooled, and when the CT temperature fluctuation amount is 25 ° C. or less, it is uniformly cooled. evaluated.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
表３に示すように、通板速度が５００ｍ／ｍｉｎ以下の場合には、ＣＴ温度変動量が十分に低減されておらず（２５℃より高い）、熱延鋼板の均一な冷却が十分に行われていない。一方、通板速度が５５０ｍ／ｍｉｎ以上の場合には、ＣＴ温度変動量が２５℃以下に抑えられており、熱延鋼板の均一な冷却が行われていることが分かった。なお、特に通板速度が６００ｍ／ｍｉｎ以上の場合には、ＣＴ温度が１０℃未満（８℃、６℃）まで抑えられていることから、この条件が熱延鋼板の均一な冷却を実現するに当たって、より好ましいことが分かった。 As shown in Table 3, when the sheet feeding speed is 500 m / min or less, the CT temperature fluctuation amount is not sufficiently reduced (higher than 25 ° C.), and the hot-rolled steel sheet is sufficiently cooled uniformly. I have not been told. On the other hand, when the sheet feeding speed was 550 m / min or more, the CT temperature fluctuation amount was suppressed to 25 ° C. or less, and it was found that the hot-rolled steel sheet was uniformly cooled. In particular, when the sheet feeding speed is 600 m / min or more, the CT temperature is suppressed to less than 10 ° C. (8 ° C., 6 ° C.), so this condition realizes uniform cooling of the hot-rolled steel plate. It was found that this is more preferable.
（実施例２）
　板厚２．５ｍｍ、幅１２００ｍｍ、引張強度８００ＭＰａ及び急峻度２％の中波が形成された熱延鋼板について、仕上げ圧延の出口側温度が８８０℃となるようにスタンド間冷却を行い、冷却装置での通板速度を変更して冷却を行った。具体的には、通板速度を４００ｍ／ｍｉｎ、４５０ｍ／ｍｉｎ、５００ｍ／ｍｉｎ、５５０ｍ／ｍｉｎ、６００ｍ／ｍｉｎ、６５０ｍ／ｍｉｎに変更し、各通板速度での熱延鋼板の冷却を２０回ずつ行った。
そして、巻き取り時の熱延鋼板の温度を測定し、その温度測定結果を用いて温度変動の標準偏差の平均値（ＣＴ温度変動量）を算出した。その算出されたＣＴ温度変動量について評価を行った結果を以下の表４に示す。なお、評価基準については上記実施例１の場合と同様とし、通板速度４００ｍ／ｍｉｎの場合のみスタンド間冷却を行っていない。 (Example 2)
A hot-rolled steel sheet having a plate thickness of 2.5 mm, a width of 1200 mm, a tensile strength of 800 MPa and a steepness of 2% is cooled between stands so that the exit side temperature of finish rolling is 880 ° C. Cooling was carried out by changing the plate feeding speed. Specifically, the sheeting speed is changed to 400 m / min, 450 m / min, 500 m / min, 550 m / min, 600 m / min, and 650 m / min, and the hot-rolled steel sheet is cooled 20 times at each sheeting speed. I went one by one.
And the temperature of the hot-rolled steel plate at the time of winding was measured, and the average value (CT temperature fluctuation amount) of the standard deviation of temperature fluctuation was computed using the temperature measurement result. The results of evaluating the calculated CT temperature fluctuation amount are shown in Table 4 below. Note that the evaluation criteria are the same as in the case of Example 1, and cooling between stands is not performed only when the plate passing speed is 400 m / min.
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
　表４に示すように、通板速度が５００ｍ／ｍｉｎ以下の場合には、スタンド間冷却を行った場合でもＣＴ温度変動量が十分に低減されておらず（２５℃より高い）、熱延鋼板の均一な冷却が十分に行われていない。一方、通板速度が５５０ｍ／ｍｉｎ以上の場合には、ＣＴ温度変動量が２５℃以下に抑えられており、熱延鋼板の均一な冷却が行われていることが分かった。 As shown in Table 4, when the sheet passing speed is 500 m / min or less, the CT temperature fluctuation amount is not sufficiently reduced (higher than 25 ° C.) even when the cooling between the stands is performed, and the hot-rolled steel sheet The uniform cooling is not sufficiently performed. On the other hand, when the sheet feeding speed was 550 m / min or more, the CT temperature fluctuation amount was suppressed to 25 ° C. or less, and it was found that the hot-rolled steel sheet was uniformly cooled.
　また、スタンド間冷却を行った場合（即ち、表４に示す場合）には、比較的硬度の高い（引張強度８００ＭＰａ）熱延鋼板に対してもＣＴ温度変動量が抑えられている。即ち、熱延鋼板の冷却時の通板速度を５５０ｍ／ｍｉｎ以上とすることに加え、仕上圧延機でのスタンド間圧延を実施することで、あらゆる鋼材、特に硬度の高い鋼材に対しても均一な冷却が可能となることが分かった。 In addition, when inter-stand cooling is performed (that is, as shown in Table 4), the CT temperature fluctuation amount is suppressed even for a hot rolled steel sheet having a relatively high hardness (tensile strength of 800 MPa). That is, in addition to setting the sheeting speed during cooling of the hot-rolled steel sheet to 550 m / min or more, it is uniform for all steel materials, particularly steel materials with high hardness, by carrying out inter-stand rolling with a finish rolling mill. It became clear that it was possible to cool.
　本発明は、仕上圧延機で熱間圧延され、圧延方向に表面高さが変動する波形状が形成された熱延鋼板を冷却する際に有用である。 The present invention is useful when cooling a hot-rolled steel sheet that has been hot-rolled by a finish rolling mill and has a corrugated shape whose surface height varies in the rolling direction.
１、２　　熱間圧延設備
　　１１、１１１　加熱炉
　　１２、１１２　粗圧延機
　　１２ａ、１１２ａ　ワークロール
　　１２ｂ、１１２ｂ　４重圧延機
　　１３、１１３　仕上圧延機
　　１３ａ、１１３ａ　仕上げ圧延ロール
　　１４、１１４　冷却装置
　　１４ａ、１１４ａ　上側冷却装置
　　１４ｂ、１１４ｂ　下側冷却装置
　　１５、１１５　巻取装置
　　１６、１１６　幅方向圧延機
　　３１、１３１　冷却口
　　３２、１３２　搬送ロール
　　４０　温度計
　　４１　形状計
　　５０　制御装置
　　５１　平均温度算出部
　　５２　変動速度算出部
　　５３　制御方向決定部
　　５４　冷却抜熱量合計値調整部
　　Ｈ　　熱延鋼板
　　Ｓ　　スラブ
　　Ｚ１、Ｚ２　分割冷却区間 1, 2 Hot rolling equipment 11, 111 Heating furnace 12, 112 Rough rolling mill 12a, 112a Work roll 12b, 112b Quadruple rolling mill 13, 113 Finishing rolling mill 13a, 113a Finishing rolling roll 14, 114 Cooling device 14a, 114a Upper cooling device 14b, 114b Lower cooling device 15, 115 Winding device 16, 116 Width rolling mill 31, 131 Cooling port 32, 132 Conveying roll 40 Thermometer 41 Shape meter 50 Controller 51 Average temperature calculation unit 52 Fluctuating speed Calculation part 53 Control direction determination part 54 Cooling heat removal amount total value adjustment part H Hot-rolled steel sheet S Slab Z1, Z2 Division | segmentation cooling area

Claims (5)


  1. 仕上圧延機で熱間圧延された熱延鋼板を、その通板経路上に設けられた冷却区間において冷却する熱延鋼板冷却装置であって、
    前記冷却区間の下流側における前記熱延鋼板の温度を測定する温度計と；
    前記冷却区間の下流側における前記熱延鋼板の形状を測定する形状計と；
    前記冷却区間において前記熱延鋼板の上面を冷却する上側冷却装置と；
    前記冷却区間において前記熱延鋼板の下面を冷却する下側冷却装置と；
    前記温度計から得られる前記熱延鋼板の温度測定結果と前記形状計から得られる前記熱延鋼板の形状測定結果とに基づいて、前記上側冷却装置及び前記下側冷却装置を制御することにより、前記冷却区間における前記熱延鋼板の上面冷却抜熱量と下面冷却抜熱量との少なくとも一方を制御する制御装置と；
    を備え、
    前記制御装置は、
    前記温度測定結果に基づいて前記冷却区間の下流側における前記熱延鋼板の温度の時系列平均値を平均温度として算出する平均温度算出部と；
    前記形状測定結果に基づいて前記冷却区間の下流側における前記熱延鋼板の変動速度を算出する変動速度算出部と；前記熱延鋼板の鉛直方向の上向きを正とした場合において、前記変動速度が正の領域で、前記熱延鋼板の波形状１周期以上の範囲の前記平均温度に対して前記熱延鋼板の温度が低い場合は、前記上面冷却抜熱量が減少する方向及び前記下面冷却抜熱量が増加する方向の少なくとも一方を制御方向として決定し、前記平均温度に対して前記熱延鋼板の温度が高い場合は、前記上面冷却抜熱量が増加する方向及び前記下面冷却抜熱量が減少する方向の少なくとも一方を前記制御方向として決定し、

    前記変動速度が負の領域で、前記平均温度に対して前記熱延鋼板の温度が低い場合は、前記上面冷却抜熱量が増加する方向及び前記下面冷却抜熱量が減少する方向の少なくとも一方を前記制御方向として決定し、前記平均温度に対して前記熱延鋼板の温度が高い場合は、前記上面冷却抜熱量が減少する方向及び前記下面冷却抜熱量が増加する方向の少なくとも一方を前記制御方向として決定する制御方向決定部と；
    前記制御方向決定部にて決定された前記制御方向に基づいて、前記冷却区間における前記熱延鋼板の前記上面冷却抜熱量と前記下面冷却抜熱量との合計値を調整する冷却抜熱量合計値調整部と；を含むことを特徴とする熱延鋼板冷却装置。
    A hot-rolled steel sheet cooling device that cools a hot-rolled steel sheet hot-rolled by a finish rolling mill in a cooling section provided on the sheet-passing path,
    A thermometer for measuring the temperature of the hot-rolled steel sheet on the downstream side of the cooling section;
    A shape meter for measuring the shape of the hot-rolled steel sheet on the downstream side of the cooling section;
    An upper cooling device for cooling the upper surface of the hot-rolled steel sheet in the cooling section;
    A lower cooling device for cooling the lower surface of the hot-rolled steel sheet in the cooling section;
    By controlling the upper cooling device and the lower cooling device based on the temperature measurement result of the hot-rolled steel plate obtained from the thermometer and the shape measurement result of the hot-rolled steel plate obtained from the shape meter, A control device for controlling at least one of an upper surface cooling heat removal amount and a lower surface cooling heat removal amount of the hot-rolled steel sheet in the cooling section;
    With
    The control device includes:
    An average temperature calculation unit that calculates, as an average temperature, a time-series average value of the temperature of the hot-rolled steel sheet on the downstream side of the cooling section based on the temperature measurement result;
    A fluctuation speed calculation unit that calculates a fluctuation speed of the hot-rolled steel sheet on the downstream side of the cooling section based on the shape measurement result; and when the upward direction in the vertical direction of the hot-rolled steel sheet is positive, the fluctuation speed is In the positive region, when the temperature of the hot-rolled steel sheet is lower than the average temperature in the range of one or more wave shapes of the hot-rolled steel sheet, the direction of decreasing the upper surface cooling heat removal amount and the lower surface cooling heat removal amount Is determined as a control direction, and when the temperature of the hot-rolled steel sheet is higher than the average temperature, the upper surface cooling heat removal amount increases and the lower surface cooling heat removal amount decreases. Is determined as the control direction,

    When the temperature of the hot-rolled steel sheet is lower than the average temperature in a region where the fluctuation speed is negative, at least one of the direction in which the upper surface cooling heat removal amount increases and the direction in which the lower surface cooling heat removal amount decreases is When the temperature of the hot-rolled steel sheet is determined as a control direction and the average temperature is higher, at least one of the direction in which the upper surface cooling heat removal amount decreases and the direction in which the lower surface cooling heat removal amount increases is set as the control direction. A control direction determining unit to determine;
    Cooling heat removal total value adjustment for adjusting the total value of the upper surface cooling heat removal amount and the lower surface cooling heat removal amount of the hot-rolled steel sheet in the cooling section based on the control direction determined by the control direction determination unit A hot-rolled steel sheet cooling device.
  2. 　前記熱延鋼板上における前記温度計の温度測定箇所と前記形状計の形状測定箇所との位置ずれが５０ｍｍ以内であることを特徴とする請求項１に記載の熱延鋼板冷却装置。
    The hot-rolled steel sheet cooling apparatus according to claim 1, wherein a positional deviation between a temperature measurement location of the thermometer and a shape measurement location of the shape meter on the hot-rolled steel plate is within 50 mm.
  3. 前記冷却区間における前記熱延鋼板の通板速度は、５５０ｍ／ｍｉｎ以上から機械的な限界速度以下の範囲内に設定されていることを特徴とする請求項１または２に記載の熱延鋼板冷却装置。 The hot-rolled steel sheet cooling according to claim 1 or 2, wherein the sheet-passing speed of the hot-rolled steel sheet in the cooling section is set within a range of 550 m / min or more to a mechanical limit speed or less. apparatus.
  4. 前記熱延鋼板の引張強度は８００ＭＰａ以上であることを特徴とする請求項３に記載の熱延鋼板冷却装置。 The hot-rolled steel sheet cooling device according to claim 3, wherein the hot-rolled steel sheet has a tensile strength of 800 MPa or more.
  5. 前記仕上圧延機は複数の圧延スタンドから構成されており、互いに隣合う前記圧延スタンドの間に、前記熱延鋼板の補助冷却を行う補助冷却装置をさらに備えることを特徴とする請求項３に記載の熱延鋼板冷却装置。 The said finishing mill is comprised from the some rolling stand, and is further provided with the auxiliary | assistant cooling device which performs auxiliary | assistant cooling of the said hot-rolled steel plate between the said rolling stands adjacent to each other. Hot rolled steel sheet cooling device.
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Families Citing this family (5)

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Publication number Priority date Publication date Assignee Title
CN106734262A (en) * 2016-12-14 2017-05-31 四川德胜集团钒钛有限公司 A kind of cooling device of milling train
CN107876579A (en) * 2017-12-06 2018-04-06 江阴戴勒姆动力设备有限公司 One kind is around piece ratio-frequency welding feed arrangement
CN108687156A (en) * 2018-05-03 2018-10-23 东莞市润华铝业有限公司 A kind of cooling device of aluminium section bar
CN110860567A (en) * 2019-11-27 2020-03-06 西南铝业（集团）有限责任公司 Material temperature measuring method and device and computer readable storage medium
CN115418474B (en) * 2022-09-02 2023-08-08 福建三宝钢铁有限公司 HRB500E segmented aerosol cooling process

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05337505A (en) 1992-06-11 1993-12-21 Kawasaki Steel Corp Method for controlling cooling of material to be rolled in hot rolling
JPH06328117A (en) 1993-05-18 1994-11-29 Nippon Steel Corp Method for injecting water in rot cooling of continuous hot rolling
JPH0763750B2 (en) * 1988-12-28 1995-07-12 新日本製鐵株式会社 Cooling control device for hot rolled steel sheet
JP2003048003A (en) 2001-07-31 2003-02-18 Nkk Corp Method for manufacturing hot-rolled steel sheet
JP2005074463A (en) 2003-08-29 2005-03-24 Nippon Steel Corp Cooling method of steel plate
JP2005271052A (en) 2004-03-25 2005-10-06 Jfe Steel Kk Hot-rolling method
JP2011073054A (en) * 2009-10-02 2011-04-14 Nippon Steel Corp Method and apparatus for cooling hot-rolled steel sheet

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0729139B2 (en) * 1988-12-28 1995-04-05 新日本製鐵株式会社 Cooling control device for hot rolled steel sheet
JPH0761493B2 (en) * 1988-12-28 1995-07-05 新日本製鐵株式会社 Cooling control device for hot rolled steel sheet
EP2070608B1 (en) * 2007-07-19 2012-09-05 Nippon Steel Corporation Method of cooling control, cooling control unit and cooling water quantity computing unit
BR112012004729B1 (en) * 2009-12-16 2021-07-20 Nippon Steel Corporation METHOD FOR COOLING A HOT ROLLED STEEL STRIP
EP2361699A1 (en) * 2010-02-26 2011-08-31 Siemens Aktiengesellschaft Method for cooling sheet metal with a cooling section, cooling section and control and/or regulating device for a cooling section
WO2011111663A1 (en) * 2010-03-11 2011-09-15 住友金属工業株式会社 Hot-rolled steel sheet manufacturing method and manufacturing device
JP7063750B2 (en) 2018-07-10 2022-05-09 ファナック株式会社 Temperature estimation device, life evaluation device, and robot system

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0763750B2 (en) * 1988-12-28 1995-07-12 新日本製鐵株式会社 Cooling control device for hot rolled steel sheet
JPH05337505A (en) 1992-06-11 1993-12-21 Kawasaki Steel Corp Method for controlling cooling of material to be rolled in hot rolling
JPH06328117A (en) 1993-05-18 1994-11-29 Nippon Steel Corp Method for injecting water in rot cooling of continuous hot rolling
JP2003048003A (en) 2001-07-31 2003-02-18 Nkk Corp Method for manufacturing hot-rolled steel sheet
JP2005074463A (en) 2003-08-29 2005-03-24 Nippon Steel Corp Cooling method of steel plate
JP2005271052A (en) 2004-03-25 2005-10-06 Jfe Steel Kk Hot-rolling method
JP2011073054A (en) * 2009-10-02 2011-04-14 Nippon Steel Corp Method and apparatus for cooling hot-rolled steel sheet

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP2929949A4

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JP5310966B1 (en) 2013-10-09
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EP2929949A4 (en) 2016-07-06
CN103987469B (en) 2015-11-25
CN103987469A (en) 2014-08-13
JPWO2014087520A1 (en) 2017-01-05
EP2929949B1 (en) 2018-04-25
BR112013028746A2 (en) 2017-01-24
KR20140100884A (en) 2014-08-18

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