CN115679054A - Full-aerosol type and mist-water mixed cooling device for intensive hot coil continuous heat treatment - Google Patents

Abstract

The invention discloses a full-aerosol cooling device for intensive hot coil continuous heat treatment, which comprises a plurality of groups of aerosol cooling mechanisms arranged in a cooling zone at the rear position of a soaking furnace, wherein the aerosol cooling mechanisms are distributed on the upper surface side and the lower surface side of strip steel and are positioned between each pair of compression rollers; each group of the aerial fog cooling mechanisms comprises a plurality of aerial fog cooling beams, and each aerial fog cooling beam is provided with a nozzle structure; the pressure and flow of the aerial fog cooling beam and the nozzle thereof are controlled on line by a PLC. The invention also discloses a mist-water mixing type device for intensive hot coil continuous heat treatment, which comprises the full-mist cooling device and a pressure water quenching spray box arranged between two adjacent mist cooling beams. The invention provides a full-mist and mist-water mixed cooling device with high cooling speed, which is used for realizing intensive continuous heat treatment production of high-strength steel.

Description

Full-aerosol type and mist-water mixed cooling device for intensive hot coil continuous heat treatment

Technical Field

The invention relates to the technical field of heat treatment, in particular to a full-aerosol-type and mist-water mixed cooling device for intensive hot-coil continuous heat treatment.

Background

In order to adapt to the situations of green manufacturing, low-carbon economy and environmental protection policies, engineering machinery, dump trucks, cash trucks and the like gradually change to the aspects of light product structures, upgrading, long service life and the like, the requirements of high-strength products with higher strength, higher wear resistance and longer service life are greatly improved, and the field of hot-rolled thin-specification ultrahigh-strength steel with the thickness of 2-6 mm shows huge market space.

Under the condition of hot continuous rolling, the production of gigabit-class thin-specification ultrahigh-strength steel by on-line quenching requires higher cooling speed and lower coiling temperature, the coiling temperature at the middle and low temperatures is not controlled at present, the strip steel plate shape control difficulty is high, the uniformity of the structure and the performance is poor, and the market requirements of high-strength steel with high performance and high plate shape cannot be met. Meanwhile, the thin hot rolling speed is high, and adverse effects are brought to the stability of the through plate and the safety of coiling equipment. Therefore, the thin gauge ultrahigh strength steel is not suitable for being produced by adopting a hot continuous rolling on-line quenching mode.

At present, thin-specification ultrahigh-strength steel is generally produced at home and abroad in an off-line heat treatment mode, namely, after a flat cutting plate is rolled up in a hot mode, heat treatment such as heating, quenching, tempering and the like is carried out in a single steel plate mode. The quenching machine generally adopts water-cooling quenching, is provided with high-pressure slit jet and pressure jet, optimizes the quenching plate shape by adjusting the water-to-water ratio, the running speed of the steel plate and the height of a frame, the running speed of the steel plate can reach 75m/min to the maximum, and basically does not need to consider the performance problem caused by forming tempered martensite by returning temperature in the quenching process. The production mode has mature technology and stable quality, but has large investment, wide occupied area, long flow, low production efficiency of single sheet and high production cost.

The intensive hot coil continuous heat treatment technology can greatly shorten the occupied area of a unit, improve the production efficiency, reduce the energy consumption and reduce the environmental pollution, and is a green production technology. However, the intensive production line layout is adopted, so that the traveling speed of the hot coil is relatively low, generally less than 10m/min, the traveling speed cannot be adjusted, the hot coil is easy to return to the temperature to form tempered martensite in the continuous quenching process, the performance problem is caused, the thin steel coil is too high in water quenching speed and poor in uniformity, the steel coil is easy to quench crack, the plate shape is difficult to control, and great difficulty is brought to the type selection and process layout design of a quenching device.

In the existing patent application, for example, chinese patent CN102492824a discloses a cooling method for continuous heat treatment of high-strength steel, which adopts a cooling method of air-jet slow cooling, air-mist cooling and slit nozzle water cooling, and mainly aims at continuous annealing treatment quenching of cold-rolled steel coils, wherein the thickness of the cold-rolled steel coils is less than 2mm, the running speed of strip steel is high, and cooling lines are arranged long. For continuous quenching of a low-speed hot coil with the thickness of 2-6 mm, the gas fog cooling rate is insufficient (the gas fog cooling rate is 10-15 ℃/s, the water spray cooling rate is 40 ℃/s), the performance problem is easily caused by temperature return, the water-cooling quenching is easy to crack, the flow regulation range of a slit nozzle is small, and the requirements of flexible quenching and multi-path quenching cannot be met.

For example, chinese patent CN102424902a discloses a continuous heat treatment method for a high-strength steel strip or plate, which describes a heat treatment process from heating, quenching to tempering for a hot-rolled steel coil or plate, wherein the quenching process employs a gas-water mixing cooling device, and a spray head of the gas-water mixing cooling device can realize adjustable control from gas-water mixing to complete water spraying. The patent does not further describe the details, parameters and layout design of the spray head device, and from the implementation, for 3mm strip steel, the gas fog cooling can only reach the cooling speed of 10 ℃/s, and the process cooling speed required by high-strength steel cannot be reached, and in addition, the spray head can be adjusted from gas fog to water spray, and the cooling uniformity is difficult to ensure.

For example, chinese patent CN101935750a discloses a production process of a high-performance steel plate heat treatment unit, but only mentions that an aerosol cooling section is used, and does not describe any details of arrangement, parameters and the like of the aerosol cooling section, nor describe the cooling speed that the aerosol section can achieve, and the control of the cooling speed is only adjusted by adjusting the on/off position of each row of aerosol spray pipes, and there is no control of the side, middle and side in the transverse direction (strip steel width direction), and there is no fine control of the pressure, flow and the like of water and water.

For example, the Chinese patent CN1413779A discloses a cooling system for a medium plate below an on-line medium temperature region, but the cooling speed is only 1-5 ℃/s, and the cooling system is only applied to the working condition below 550 ℃, and can not meet the requirement of producing high-strength steel.

For example, chinese patent CN106350640a discloses a method for continuously quenching cold-rolled steel strip, which only mentions the use of aerosol cooling from the process perspective, and does not describe any details of the arrangement, parameters, etc. of the aerosol cooling section.

For example, the Chinese patent CN109022734A discloses an online strip steel heat treatment device and a heat treatment method, which use 'an ultra-fast cooling section + a layer cooling section' and do not relate to aerial fog cooling.

For example, chinese patent CN102327831A discloses an air-mist spray pipe for cooling plate and strip materials, which aims to combine an air-mist spray nozzle with a subsequent air-water spray pipe to form an integral non-standard part. But the reality is not as good as the reality of using the aerosol nozzle with the standard structure form, the installation interfaces of the nozzle with the standard structure form are the same, the interchangeability can be increased, more importantly, the standard structure form is adopted, so that different aerosol nozzles can be flexibly replaced according to different cooling requirements, and different process requirements can be flexibly met.

For another example, chinese patent CN102424902a discloses an off-line thermal treatment vapor-fog cooling system for thin and medium plates, which describes a non-standard slit nozzle for vapor-fog cooling, and does not describe the actual cooling speed, and the upper and lower slit nozzles of each group of cooling beams have no "middle-edge" adjusting function, and it is difficult to control the slit precision and cooling speed in the plate width direction; and the gap width is fixed, and the cooling speed is difficult to adjust according to the process requirement.

From the above-mentioned patent and practical field application, the highest cooling rate of pressure water quenching is suitable for thick plates or thick tubes, but for thin strip steel quenching, the cooling rate is too fast, so that quenching cracks are easily caused, uniformity is difficult to ensure, and thus, it is difficult to control the shape of the strip. The commonly used gas spray cooling technology for cold rolling and continuous annealing has good cooling uniformity, but the cooling speed is low, so that the method is only suitable for extremely thin specifications below 2mm and cannot meet the high cooling speed requirement required by hot coil quenching with the thickness of 2-10 mm.

At present, no mature quenching cooling device and control method for continuous hot coil heat treatment are applied, and particularly the quenching cooling device and control method for intensive continuous heat treatment of 2-10 mm strip steel at low running speed are blank.

Through careful analysis, the characteristics of aerial fog cooling are as follows: although the cooling speed is slightly lower than that of water quenching, the cooling uniformity is good, and the accurate control of the cooling speed can be realized by adjusting the pressure and the flow on line. If the mechanism of the aerial fog cooling is carefully analyzed, the deep optimization of the aerial fog cooling device can be carried out, and the cooling capacity can be greatly improved, so that the requirements of quick and uniform cooling required by the continuous heat treatment of the thin hot steel coil can be met.

Disclosure of Invention

In view of the above-mentioned defects in the prior art, the present invention aims to provide an all-aerosol-type and mist-water mixed cooling device for intensive hot coil continuous heat treatment, and an all-aerosol-type and mist-water mixed cooling device with high cooling speed, so as to realize intensive continuous heat treatment production of high-strength steel.

In order to achieve the purpose, the invention adopts the following technical scheme:

on one hand, the full-aerosol cooling device for intensive hot coil continuous heat treatment comprises a plurality of groups of aerosol cooling mechanisms arranged in a cooling zone at the rear position of a soaking furnace, wherein the aerosol cooling mechanisms are distributed on the upper surface side and the lower surface side of strip steel and are positioned between each pair of compression rollers;

each group of the aerial fog cooling mechanisms comprises a plurality of aerial fog cooling beams, and each aerial fog cooling beam is provided with a nozzle assembly;

the pressure and flow of the aerial fog cooling beam and the nozzle assembly are controlled on line by a PLC.

Preferably, the nozzle assembly comprises a water inlet pipe, a compressed air inlet pipe and a plurality of rows of aerosol nozzles communicated with the water inlet pipe and the compressed air inlet pipe respectively;

the fan-shaped jet flow of the aerial fog nozzle is arranged towards the surface of the strip steel.

Preferably, the aerosol nozzle is an internal mixing nozzle or an external mixing nozzle.

Preferably, the gas spray nozzle is a fan-shaped nozzle, and the deflection angle of the fan-shaped jet flow of the gas spray nozzle and/or the gas spray nozzle in the width direction of the strip steel is 15-60 degrees.

Preferably, two or more rows of the aerosol nozzles are arranged on the water inlet pipe.

Preferably, a water mist baffle is further arranged between the cooling area and the soaking pit, and the water mist baffle is distributed on the upper surface side and the lower surface side of the strip steel.

Preferably, the fan angle beta of the aerosol nozzle is 45-90 degrees; the height difference H between the strip steel and the surface of the strip steel is 80-150 mm; the width B of the fan flow which is beaten on the steel plate can be calculated from beta and H; the air and mist exhaust nozzles need to deflect a certain angle delta to avoid mutual interference of fan flows; the overlap OV of the fan-shaped jet flow between the nozzle and the exhaust fog nozzle is a key parameter for ensuring the cooling uniformity in the transverse direction (the plate width direction); the transverse distance D of the aerosol nozzles is ensured to be 1/3-1/4 of OV value B; the longitudinal distance L (along the strip steel advancing direction) of each exhaust fog nozzle has great influence on the cooling speed, and the L value is reduced as much as possible so as to prevent the strip steel from returning to the temperature between the gaps of the two groups of the fog nozzles and influencing the cooling speed.

On the other hand, the mist-water mixed cooling device for intensive hot coil continuous heat treatment comprises the full-mist cooling device and a pressure water quenching spray box arranged between two adjacent mist cooling beams;

the pressure water quenching spray box cools the strip steel from the upper side and the lower side;

and a plurality of rows of water nozzles are arranged on one side of the surface of the strip steel facing the pressure water quenching spraying box.

Preferably, the pressure water quenching spray box is a straight spray box or an inclined spray box.

Preferably, the direct jet of the water nozzles on the direct injection box or the oblique jet of the water nozzles on the oblique injection box is directed toward the surface of the strip steel;

the cooling speed of the fog-water mixed cooling device is more than or equal to 60 ℃/s.

The all-gas-mist and mist-water mixed cooling device for intensive hot coil continuous heat treatment provided by the invention can realize quenching and cooling production with the thickness of 2-12 mm of an intensive heat treatment production line, expand steel specification by applying flexible quenching and multi-path quenching, improve product performance, achieve good quenching plate shape through a plate shape control technology, and realize full-automatic quenching cooling and accurate control through a model control technology.

Drawings

FIG. 1 is a schematic view of a full aerosol cooling device according to the present invention, wherein the deflection angle of the aerosol fan nozzle is 15 °;

FIG. 2 is a schematic view of the deflection angle of the fan-shaped nozzle for spraying gas in the full spraying type cooling device of the present invention is 40 °;

FIG. 3 is a schematic view of a nozzle assembly of the all-aerosol cooling device of the present invention, wherein (a) the water inlet pipe is provided with 2 exhaust mist nozzles, and (b) the water inlet pipe is provided with 4 exhaust mist nozzles;

FIG. 4 is a schematic view of the deflection angle of the fan-shaped nozzle of the air mist in the full air mist cooling device of the present invention, wherein the arrow indicates the traveling direction of the strip steel;

FIG. 5 is a schematic view of a pressure water quenching spray box of the mist-water hybrid cooling device according to the present invention being a tilted spray box;

FIG. 6 is a schematic view of a pressure water quenching spray box in the mist-water hybrid cooling device according to the present invention being a straight spray box;

FIG. 7 is a parameter diagram of the arrangement of the mist nozzles in the all-mist cooling device and the mist-water hybrid cooling device according to the present invention.

Detailed Description

In order to better understand the technical solutions of the present invention, the following further describes the technical solutions of the present invention with reference to the accompanying drawings and examples.

Referring to fig. 1 and 2, the full-aerosol cooling device for intensive hot-rolling continuous heat treatment of steel materials with thickness of 2-7 mm and good heat conductivity provided by the invention comprises a plurality of groups of aerosol cooling mechanisms arranged in a cooling zone 2 at the rear position of a soaking furnace 1, wherein the aerosol cooling mechanisms are distributed on the upper surface side and the lower surface side of a strip steel 3 and are positioned between each pair of compression rollers 4.

Every aerial fog cooling body of group includes many aerial fog chilled beams 5, is equipped with nozzle assembly on every aerial fog chilled beam 5, and aerial fog chilled beam 5 and nozzle assembly's pressure and flow are by PLC on-line control.

The gas mist cooling mechanism is arranged as close to the soaking furnace 1 as possible to reduce air cooling after furnace discharge.

A water mist baffle 6 is arranged between the soaking pit 1 and the cooling area 2, and the water mist baffle 6 is distributed on the upper surface side and the lower surface side of the strip steel 3, so that the strip steel 3 is prevented from being cooled in advance by scattered water mist, the open cooling temperature is low, and the mechanical property of the strip steel 3 is influenced.

The individual aerosol-cooled beams 5 are arranged against the press rolls 4 to reduce the air cooling section.

Multiple rows of gas mist cooling beams 5 are arranged between every two pairs of compression rollers 4, such as 4 groups multiplied by 4 groups shown in fig. 3, and can also be arranged in other forms according to the temperature reduction process requirements of different steel types, such as 4 groups multiplied by 3 groups multiplied by 2 groups.

Each aerial fog cooling beam 5 is segmented according to 'edge part, middle part and edge part' in the width direction (transverse direction) of the strip steel 3, the end pressure and flow of the corresponding water inlet pipe and the corresponding compressed air pipe can be controlled on line by a PLC (programmable logic controller) so as to carry out 'edge part' on-line regulation on the cooling speed of the strip steel 3 according to the process requirements.

Referring to fig. 3, the nozzle assembly includes a water inlet pipe 7, a compressed air pipe 9, and a plurality of rows of aerosol nozzles 8 connected to the water inlet pipe 7 and the compressed air pipe 9.

The jets 801 of the gas mist nozzles 8 are all arranged toward the surface of the strip steel 3.

In order to arrange the aerosol nozzles 8 as densely as possible along the traveling direction of the strip steel 3, the invention utilizes the principle that the area and the diameter form a square relation, the structure of a 'one-beam and multi-row nozzle' can be realized in a smaller space by properly increasing the pipe diameter of the water inlet pipe 7 and the pipe diameter of the compressed air pipe 9, and the space is saved by arranging the water inlet pipe 7 and the compressed air pipe 9 up and down to shorten the occupied distance of each aerosol cooling beam 5 in the traveling direction (longitudinal direction) of the strip steel 3 as much as possible and increase the number of the aerosol nozzles 8 in the unit longitudinal length, as shown in figure 3, (a) is a beam 2 exhaust aerosol nozzle 8, and (b) is a beam 4 exhaust aerosol nozzle 8.

The gas mist nozzle 8 may be an internal mixing type nozzle or an external mixing type nozzle. The two types of nozzles have the advantages that the atomized particles of the internal mixing type nozzle are finer; when the external mixing type nozzle is adjusted, the water pressure and the air pressure are mutually independent, and are not interfered by the change of the other party, so that the PLC control is more convenient.

Referring to fig. 4, the deflection angle δ of the jet flow 801 of the gas spray nozzle 8 with respect to the strip width direction is 15 ° to 60 ° (the arrow in the figure indicates the strip running direction), and the gas spray nozzles 8 in the same row are deflected by a certain deflection angle δ so as not to interfere with the fan flow, and when the deflection angle δ of the jet flow 801 of the gas spray nozzle 8 with respect to the strip width direction is 15 ° as shown in fig. 1. When necessary, the deflection angle delta is increased, so that the jet flow 801 of the front and rear exhaust mist nozzles 8 is approximately and continuously arranged, and when the deflection angle delta between the jet flow 801 of the mist nozzle 8 and the water inlet pipe 7 shown in fig. 1 is 45 degrees, the proportion of a 'non-jet flow impact section' can be reduced, the temperature return phenomenon of the strip steel 3 is effectively avoided, and the mist cooling capacity is increased.

The full-aerosol cooling device is adopted, and the aerosol cooling speed of the wear-resistant steel with the thickness of 6mm from 800 to 200 ℃ is more than or equal to 60 ℃/s.

Referring to fig. 5 and 6, the mist-water mixed cooling device for intensive hot-coil continuous heat treatment of steel materials such as abrasion-resistant steel having a thickness of 4 to 12mm and a low thermal conductivity, which is provided by the present invention, includes a full-mist cooling device according to the present invention and a pressure water quenching tank 10 provided between two adjacent mist cooling beams 5.

The pressure water quenching spray box 10 is provided with a plurality of rows of water nozzles 11 on one side of the surface of the strip steel 3.

The advantage that the water quenching cooling ability of the aerial fog homogeneity and the pressure water quenching spray box 10 that combine full aerial fog formula cooling device is strong, cooling methods such as "pure aerial fog" or "aerial fog + water quenching" are selected in a flexible way: when the thickness of the strip steel 3 is thinner, a full gas spray cooling mode is adopted, and when the thickness of the strip steel 3 is thicker, a gas spray and water quenching cooling mode is adopted.

The pressure water quenching spray box 10 can adopt a direct spray box (on which a plurality of rows of columnar water nozzles 11 are densely arranged) or an oblique spray box (on which a plurality of rows of columnar water nozzles 11 are densely arranged), and the direct spray box and the oblique spray box are also inner sections, so that the independent control of the edge, middle and edge water pressure and flow in the width direction of the strip steel 3 can be realized.

Referring to fig. 7, the fan angle β of the mist nozzle in the all-mist cooling device and the mist-water mixed cooling device of the present invention is 45 ° to 90 °; the height difference H between the strip steel and the surface of the strip steel is 80-150 mm; the width B of the fan flow which is beaten on the steel plate can be calculated from beta and H; the air and mist exhaust nozzles need to deflect a certain angle delta to avoid mutual interference of fan flows; the overlap OV of the fan-shaped jet flow between the nozzle and the exhaust fog nozzle is a key parameter for ensuring the cooling uniformity in the transverse direction (the plate width direction); the transverse distance D of the aerosol nozzles is ensured to be 1/3-1/4 of OV value B; the longitudinal distance L (along the strip steel advancing direction) of each exhaust fog nozzle has great influence on the cooling speed, and the L value is reduced as much as possible so as to prevent the strip steel from returning to the temperature between the gaps of the two groups of the fog nozzles and influencing the cooling speed.

The inclined spraying box has the advantages that the water flow inclined spraying direction is consistent with the advancing direction of the strip steel 3, the water flow on the upper surface of the strip steel 3 cannot splash to the front of the compression roller and completely cannot flow back to the position of the soaking pit, and the requirements on the manufacturing precision and the pressure control of the compression roller 4 are not high. The advantage of directly spouting the case can arrange the spout case body between the space of each group of aerial fog chilled beam 5, only need with the water nozzle 11 imbed between the aerial fog chilled beam 5 can, can shorten the distance between each group of aerial fog chilled beam 5 as far as possible, this makes can densely arrange the aerial fog roof beam, cooling capacity when can greatly improve full aerial fog mode.

Example 1

Producing steel with thickness of 2-7 mm and good heat conductivity

By adopting the full-aerosol cooling device shown in figure 1 or figure 2 or the mist-water mixed cooling device shown in figure 5 or figure 6, the pressure water quenching spraying box 10 is kept closed, and the cooling is carried out in a full-aerosol mode, so that the cooling speed is not less than 60 ℃/s, and the optimal plate shape is obtained.

Example 2

Producing steel with thickness of 4-12 mm and good heat conductivity

By adopting the mist-water mixed cooling device shown in fig. 5 or fig. 6, the pressure water quenching spray box 10 is partially or completely opened according to the process requirements, and is cooled in a mist-water mixing mode, so that the cooling speed is ensured to be more than or equal to 60 ℃/s, and the optimal plate shape is obtained.

The invention relates to a full-gas-fog type and mist-water mixed cooling device for intensive hot coil continuous heat treatment, which is characterized in that a set of gas-fog or mist-water mixed quenching cooling device optimized according to the parameters is arranged between a heating device and a drying device for intensive thin hot coil continuous heat treatment, heated hot rolled strip steel enters the quenching cooling device area through a conveying roller way to be subjected to gas-fog cooling or gas-fog and water-cooling mixed cooling quenching treatment, the steel plate reaches a specific final cooling temperature according to a preset cooling rate curve under the condition of ensuring the plate shape and the uniform cooling, and then is sent to post-process treatment by the roller way after being dried.

It should be understood by those skilled in the art that the above embodiments are only for illustrating the present invention and are not to be used as a limitation of the present invention, and that the changes and modifications of the above embodiments are within the scope of the appended claims as long as they are within the true spirit of the present invention.

Claims (10)

1. The utility model provides a full aerial fog formula cooling device of continuous thermal treatment of intensive hot book which characterized in that: the device comprises a plurality of groups of gas fog cooling mechanisms arranged in a cooling zone at the rear position of a soaking furnace, wherein the gas fog cooling mechanisms are distributed on the upper surface side and the lower surface side of the strip steel and are positioned between each pair of compression rollers;

each group of the aerial fog cooling mechanisms comprises a plurality of aerial fog cooling beams, and each aerial fog cooling beam is provided with a nozzle assembly;

the pressure and flow of the aerial fog cooling beam and the nozzle assembly are controlled on line by a PLC.

2. The apparatus according to claim 1, wherein the apparatus comprises: the nozzle assembly comprises a water inlet pipe, a compressed air inlet pipe and a plurality of rows of aerial fog nozzles communicated with the water inlet pipe and the compressed air inlet pipe respectively;

the fan-shaped jet flow of the aerial fog nozzle is arranged towards the surface of the strip steel.

3. The apparatus according to claim 2, wherein the apparatus comprises: the aerosol nozzle is an internal mixing nozzle or an external mixing nozzle.

4. The apparatus according to claim 2, wherein the apparatus comprises: the gas spray nozzle is a fan-shaped nozzle, and the deflection angle of the fan-shaped jet flow of the gas spray nozzle and/or the gas spray nozzle in the width direction of the strip steel is 15-60 degrees.

5. The apparatus according to claim 2, wherein the apparatus comprises: the water inlet pipe is provided with two or more than two rows of the aerosol nozzles.

6. The apparatus according to claim 1, wherein the apparatus comprises: and a water mist baffle is also arranged between the cooling area and the soaking pit, and the water mist baffle is distributed on the upper surface side and the lower surface side of the strip steel.

7. The apparatus according to claim 2, wherein the apparatus comprises: the fan-shaped angle beta of the aerosol nozzle is 45-90 degrees;

the height difference H between the aerosol nozzle and the surface of the strip steel is 80-150 mm;

and a deflection angle delta is formed between the aerosol nozzles in the same row, and the deflection angle delta is 15-60 degrees.

8. The utility model provides a fog water hybrid cooling device of continuous thermal treatment of intensification heat book which characterized in that: the full-aerosol cooling device comprises the full-aerosol cooling device as claimed in any one of claims 1 to 7, and a pressure water quenching spray box arranged between two adjacent aerosol cooling beams;

and a plurality of rows of water nozzles are arranged on one side of the surface of the strip steel facing the pressure water quenching spraying box.

9. The mist-water hybrid cooling device for intensive hot coil continuous heat treatment according to claim 8, characterized in that: the pressure water quenching spray box is a straight spray box or an inclined spray box.

10. The mist-water hybrid cooling device for intensive hot coil continuous heat treatment according to claim 8, characterized in that: a direct jet flow of the water nozzles on the direct injection tank or an oblique jet flow of the water nozzles on the oblique injection tank is directed toward the surface of the strip steel;

the cooling speed of the fog-water mixed cooling device is more than or equal to 60 ℃/s.

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