CN111996462A - Longitudinal variable-thickness ultrahigh-strength ship board and production method thereof - Google Patents
Longitudinal variable-thickness ultrahigh-strength ship board and production method thereof Download PDFInfo
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- 238000004519 manufacturing process Methods 0.000 title claims abstract description 24
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 113
- 239000010959 steel Substances 0.000 claims abstract description 113
- 238000005096 rolling process Methods 0.000 claims abstract description 39
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 18
- 238000005266 casting Methods 0.000 claims abstract description 10
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 10
- 239000000126 substance Substances 0.000 claims abstract description 10
- 238000001816 cooling Methods 0.000 claims abstract description 7
- 238000007664 blowing Methods 0.000 claims abstract description 5
- 238000000034 method Methods 0.000 claims description 17
- 238000010438 heat treatment Methods 0.000 claims description 13
- 238000003723 Smelting Methods 0.000 claims description 11
- 230000008569 process Effects 0.000 claims description 11
- 238000009749 continuous casting Methods 0.000 claims description 8
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 6
- 238000010521 absorption reaction Methods 0.000 claims description 4
- 239000012535 impurity Substances 0.000 claims description 2
- 229910052742 iron Inorganic materials 0.000 claims description 2
- 229910052799 carbon Inorganic materials 0.000 abstract description 2
- 229910052719 titanium Inorganic materials 0.000 abstract description 2
- 229910052720 vanadium Inorganic materials 0.000 abstract description 2
- 229910052802 copper Inorganic materials 0.000 abstract 1
- 229910052759 nickel Inorganic materials 0.000 abstract 1
- 229910052698 phosphorus Inorganic materials 0.000 abstract 1
- 238000005728 strengthening Methods 0.000 description 9
- 230000000694 effects Effects 0.000 description 7
- 229910045601 alloy Inorganic materials 0.000 description 5
- 239000000956 alloy Substances 0.000 description 5
- 238000001556 precipitation Methods 0.000 description 5
- 238000007670 refining Methods 0.000 description 5
- 238000003466 welding Methods 0.000 description 5
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- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
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- 238000012545 processing Methods 0.000 description 1
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- 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
- B21B1/46—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 metal immediately subsequent to continuous casting
- B21B1/463—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 metal immediately subsequent to continuous casting in a continuous process, i.e. the cast not being cut before rolling
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/08—Ferrous alloys, e.g. steel alloys containing nickel
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/16—Ferrous alloys, e.g. steel alloys containing copper
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Abstract
The invention discloses a longitudinal variable-thickness ultrahigh-strength ship board and a production method thereof, wherein the steel board comprises the following chemical components: 0.060 percent to 0.120 percent of C, 0.15 percent to 0.50 percent of Si, 1.10 percent to 1.70 percent of Mn, 0.040 percent to 0.070 percent of V, 0.20 percent to 0.50 percent of Cu, 0.10 percent to 0.50 percent of Ni, 0.005 percent to 0.020 percent of Ti, 0.0120 percent to 0.0180 percent of N, less than or equal to 0.010 percent of P, less than or equal to 0.005 percent of S and 0.015 percent to 0.030 percent of Als. The molten steel is treated by nitrogen blowing in a converter or RH, the casting blank is heated to 1130-1250 ℃, and the temperature is preserved for 40-240 min; the initial rolling temperature is 1040-; the intermediate blank is rolled when the temperature is 850-910 ℃, and the rolling thickness is 1.5-2.0 times of the maximum thickness of the final LP steel plate; variable-thickness rolling is adopted, and the final rolling temperature of the steel plate is controlled to be 800-850 ℃; and air-cooling the steel plate to room temperature to obtain the final longitudinal variable thickness steel plate. The steel plate has good mechanical property uniformity along the length direction, the strength difference between thick and thin positions is within 15MPa, the toughness and plasticity are consistent, and the steel plate is suitable for longitudinal variable-thickness high-strength ship plates in any shapes.
Description
Technical Field
The invention belongs to the technical field of metal material production, and particularly relates to a longitudinal variable-thickness ultrahigh-strength ship board and a production method thereof.
Background
The longitudinal variable thickness (LP) steel plate is a steel plate having a thickness varying in a length direction, and is a steel plate having a longitudinal thickness varying by continuously changing an opening degree of a roll during rolling, and may be divided into 10 different shapes according to a thickness variation manner. The LP steel plate has a unique advantage in optimizing the design of structural sections of a hull and the like because the thickness of the LP steel plate can be changed according to the load bearing condition, and the application of the LP steel plate can not only reduce the amount of steel and the number of welding times, but also improve the operability through the equal thickening of the joint, such as omitting a backing plate and taper processing, and in recent years, the amount of the LP steel plate is increasing with the increase of the demand for the weight reduction of ships. Therefore, the LP steel plate is a reduced and economical steel plate, and is favored by manufacturers and users at home and abroad. And have resulted in a number of related production and control techniques.
A patent entitled "a method for producing a longitudinally variable thickness steel sheet", application No.: 201010282876.1, the patent provides a method for producing a longitudinally variable thickness steel plate, which produces a qualified longitudinally variable thickness steel plate by controlling the temperature difference of the upper and lower surfaces of a steel billet during discharging, the descaling pass of high pressure water, the diameter difference of the upper and lower working rolls during roll matching, adjusting the zero adaptive numerical value of a mathematical model according to the actual thickness of the steel plate, controlling the rolling speed, the opening and finishing temperature of the steel plate, the single-pass deformation of the last two passes and other technological measures. However, the patent does not control and evaluate the mechanical properties of longitudinally variable thickness steel sheets. A patent entitled "a method for producing a low-alloy longitudinally variable thickness steel sheet", application No.: 201710809565.8, which discloses a method for producing a low-alloy longitudinally variable-thickness steel plate, wherein a double-frame medium plate production line is adopted, and the longitudinal variable-thickness steel plate is produced by the procedures of rough rolling, finish rolling and the like by utilizing the quick response function of a rolling mill HGC. The mechanical properties of a longitudinal variable-thickness steel plate with the mark of Q345GJC are researched in a document which is published in 'steel structure' of the fourth stage of 2017 and is named as 'mechanical property test research of the longitudinal variable-thickness steel plate', and the Q345GJC steel plate disclosed in the document contains high alloy elements such as Nb and V in chemical components, is high in production cost and has large mechanical property difference along the thickness direction, namely, is poor in mechanical property homogeneity. The patent named '345 MPa-level LP steel plate and a production method thereof', and the application number is as follows: 201710068867.4, the patent discloses a 345MPa grade wedge-shaped steel plate with one thin end and one thick end, which is cast into a continuous casting billet with chemical components varying along the length by using two tanks of molten steel with different components, and then rolled, so that the mechanical properties of the rolled wedge-shaped steel plate tend to be uniform, but the process is complicated and only suitable for the wedge-shaped steel plate with one thin end and one thick end. The name is' 390 MPa-level LP steel plate and a production method thereof, and the application number is as follows: 201710068896.0' and a 420 MPa-grade LP steel plate and a production method thereof, application numbers: 201710068882.9, the same process is adopted to prepare 390MPa and 420MPa wedge-shaped steel plates respectively, and the defects of complex process and only suitability for wedge-shaped steel plates exist. And the production of the longitudinal variable-thickness ship plate is not reported at present.
In summary, the following problems mainly exist in the current production of longitudinally variable thickness steel plates.
1) High alloy element content and high production cost.
2) The uniformity of the mechanical property of the steel plate along the length direction is poor.
3) The production process is complex.
Disclosure of Invention
In view of the above problems and disadvantages, the invention aims to provide a longitudinal thickness-variable ultrahigh-strength ship board which has reasonable component design, strong process applicability and uniform mechanical property in the length direction.
The technical scheme of the invention is as follows:
1. the chemical components of the longitudinally variable-thickness ultrahigh-strength ship plate prepared by the invention are as follows in percentage by weight: 0.060% -0.120% of C, 0.15% -0.50% of Si, 1.10% -1.70% of Mn, 0.040% -0.070% of V, 0.20% -0.50% of Cu, 0.10% -0.50% of Ni, 0.005% -0.020% of Ti, 0.0120% -0.0180% of N, less than or equal to 0.010% of P, less than or equal to 0.005% of S, 0.015% -0.030% of Als, and the balance of Fe and inevitable impurities.
The effects of the chemical components of the present invention are described in detail below.
C: the main strengthening elements in the steel are main elements for improving the hardenability of the steel; if the content is too low, the amount of carbide and the like produced decreases, and the effect of refining grains during rolling is impaired. When the content is too high, the low-temperature toughness and weldability of the steel sheet are adversely affected. Therefore, the range of the control C of the invention is 0.060 percent to 0.120 percent by comprehensively considering factors such as cost, performance and the like
Si: the necessary elements for steel-making deoxidation have strong solid solution capability in steel and can play a certain strengthening role, but the low-temperature toughness and welding performance of the steel are seriously damaged due to too high content. The invention controls the range of Si to be 0.15 to 0.50 percent
Mn: can delay the transformation of ferrite and pearlite in steel, greatly increase the hardenability of the steel, reduce the brittle transformation temperature of the steel and improve the impact toughness, but the Mn content is too high, so that segregation is easily formed in the steel, and the plasticity and the toughness of the steel are adversely affected. Comprehensively considering, the range of Mn controlled by the invention is 1.10-1.70%
V: the main alloy elements of the invention have small influence on austenite recrystallization, and the large precipitation of V carbon and nitride can play the roles of refining and strengthening crystal grains at low temperature, thereby improving the strength of the steel plate. The range of V controlled by the invention is 0.040% -0.070%.
Cu: not only does not have adverse effect on the hardenability and toughness of a welding heat affected zone, but also can improve the strength of a base metal, greatly improve the low-temperature toughness and precipitate-Cu at a certain temperature, thereby generating precipitation strengthening on steel; however, when the Cu content is higher, the billet can generate cracks during heating or rolling, and the Cu content is controlled to be 0.20-0.50 percent.
Ni: the invention controls the range of Ni to be 0.10-0.50%.
Ti: can generate strong precipitation strengthening effect, improve the strength of steel and prevent austenite from recrystallizing; meanwhile, the grain refining effect can be generated, and the yield strength of the steel is improved; in addition, the addition of titanium can prevent the growth of crystal grains of the billet in the heating, rolling and welding processes, and improve the toughness of the base metal and the welding heat affected zone. Comprehensively, the range of Ti controlled by the invention is 0.005-0.020%.
N: in the steel, N mainly exists in a free state and a compound state, the former existence has adverse effect on the toughness of the steel plate, and the latter existence has good effect on the comprehensive performance of the steel plate. In the case of a steel containing V, most of V does not sufficiently exhibit its precipitation strengthening action when nitrogen is deficient in the steel. In addition, the nitrogen-containing steel not only eliminates the cost increase caused by degassing and refining denitrogenation in the steel-making process, but also can fully play the role of microalloy elements by increasing nitrogen in the steel, saves the using amount of alloying elements and greatly reduces the production cost. The invention controls the range of N to be 0.0120% -0.0180%.
Al: the strong deoxidizer produces highly fine and ultra-microscopic oxides in steel, and plays a role in refining grains. The range of Als controlled by the invention is 0.015-0.030%.
2. The specific process method of the invention comprises the following steps: comprises smelting, continuous casting, heating by a heating furnace and rolling, and is characterized in that:
(1) the steel with the components is smelted, and the smelting process route is as follows: the method comprises the steps of molten iron pretreatment, converter smelting, LF-RH continuous casting, and nitrogen blowing treatment in a converter or RH to control the nitrogen content in the smelting steel, wherein the treatment time is more than or equal to 10 min.
(2) Continuously casting the molten steel obtained in the step (1) to prepare a continuous casting billet, and controlling the superheat degree of a tundish to be 20-30 ℃.
(3) And (3) heating the casting blank obtained in the step (2) to 1130-1250 ℃, and preserving heat for 40-240 min.
(4) Rolling of
a) A rough rolling stage: and rolling the heated casting blank to the thickness of 2.0-3.0 times of the maximum thickness of the final LP steel plate, wherein the initial rolling temperature of the casting blank is 1040-1120 ℃. And obtaining an intermediate billet after rolling is finished.
b) And (3) intermediate rolling stage: and c), heating the intermediate blank obtained in the step a to 850-910 ℃, and then rolling the intermediate blank until the rolling thickness is 1.5-2.0 times of the maximum thickness of the final steel plate.
c) And (3) finish rolling stage: rolling by variable thickness according to the required thickness and inclination, controlling the final rolling temperature of the steel plate to be 800-850 ℃, and controlling the temperature according to the thickness of the steel plate
The temperature at mm is controlled, wherein: t is tmaxIs the most importantMaximum thickness of the final steel plate, tminThe minimum thickness of the final steel sheet.
(5) The rolled steel plate is accelerated and cooled, the start cooling temperature is 700-780 ℃, the re-reddening temperature is 550-720 ℃, and the temperature is determined according to the thickness of the steel plate
The temperature at mm was controlled.
(6) And (5) air-cooling the steel plate obtained in the step (5) to room temperature to obtain a final longitudinal thickness-variable steel plate.
The invention realizes the low-cost production of the longitudinal variable-thickness high-strength steel plate by designing the chemical components and the rolling process of the longitudinal variable-thickness steel plate, and has excellent mechanical properties. The yield strength of the material is more than 460MPa, the elongation after fracture is more than 25.0 percent, the impact absorption energy at minus 40 ℃ is more than 150J, the impact absorption energy at minus 60 ℃ is more than 100J, the aging impact performance at minus 40 ℃ is more than 110J, and the aging impact performance at minus 60 ℃ is more than 80J. The method overcomes the defect of uneven mechanical property caused by thickness difference in the length direction of the steel plate by controlling the change of the number of precipitated phases at different positions in the length direction of LP, thereby achieving the purpose of controlling the uniformity of the mechanical property in the length direction, and finally the steel plate has good uniformity of the mechanical property in the length direction, the strength difference between thick and thin positions is within 15MPa, and the toughness and plasticity are consistent.
Drawings
FIG. 1 is a metallographic structure of a thin end of a steel plate in example 3;
FIG. 2 the thick end metallographic structure of the steel plate in example 3;
FIG. 3 example 3 the distribution of precipitated phases at the thin end of the steel sheet;
FIG. 4 shows the distribution of precipitated phases at the thick end of the steel sheet in example 3.
Detailed Description
The following examples are only some of the best modes for carrying out the invention and do not limit the scope of the invention and the technical means described above.
Smelting is carried out according to the designed chemical composition range, the chemical composition is shown in table 1, and the smelting process is shown in table 2.
TABLE 1 chemical composition (wt%) of steels of examples of the present invention
| Numbering | C | Si | Mn | P | S | V | Cu | Ni | Ti | N | Als |
| 1 | 0.064 | 0.18 | 1.63 | 0.006 | 0.002 | 0.068 | 0.48 | 0.41 | 0.016 | 0.0174 | 0.021 |
| 2 | 0.076 | 0.23 | 1.46 | 0.003 | 0.001 | 0.054 | 0.32 | 0.33 | 0.013 | 0.0165 | 0.023 |
| 3 | 0.088 | 0.32 | 1.38 | 0.001 | 0.003 | 0.048 | 0.43 | 0.18 | 0.009 | 0.0154 | 0.027 |
| 4 | 0.112 | 0.48 | 1.12 | 0.005 | 0.002 | 0.043 | 0.24 | 0.22 | 0.011 | 0.0148 | 0.017 |
| 5 | 0.103 | 0.37 | 1.26 | 0.002 | 0.004 | 0.052 | 0.27 | 0.26 | 0.007 | 0.0133 | 0.029 |
| 6 | 0.092 | 0.29 | 1.52 | 0.007 | 0.001 | 0.062 | 0.37 | 0.36 | 0.018 | 0.0126 | 0.019 |
TABLE 2 examples Steel smelting Process
| Numbering | Nitrogen blowing treatment time/min | Degree of superheat/. degree.C |
| 1 | 36 | 22 |
| 2 | 32 | 26 |
| 3 | 28 | 21 |
| 4 | 29 | 27 |
| 5 | 19 | 29 |
| 6 | 17 | 28 |
The obtained continuous casting billet is subjected to processes of heating, rolling and the like to prepare the longitudinal variable thickness steel plate. The heating process is shown in table 3 and the rolling process is shown in table 4.
Table 3 heating process of steel of examples of the present invention
| Numbering | Minimum thickness/mm | Maximum thickness/mm | Heating temperature/. degree.C | Holding time/min |
| 1 | 15 | 45 | 1150 | 42 |
| 2 | 20 | 50 | 1180 | 60 |
| 3 | 14 | 30 | 1240 | 210 |
| 4 | 40 | 60 | 1210 | 235 |
| 5 | 35 | 60 | 1190 | 150 |
| 6 | 30 | 55 | 1160 | 100 |
TABLE 4 Rolling Process of steels of examples of the invention
The mechanical properties of the steels corresponding to the examples of the invention are shown in table 5. The aging process comprises the following steps: deforming by 5 percent, and keeping the temperature at 250 ℃ for 1 h.
TABLE 5 mechanical Properties of steels of examples of the invention
FIGS. 1-2 are metallographic photographs of the thin and thick ends of the steel sheet of example 3 illustrating that the thin end of the steel sheet has a smaller grain size than the thick end, and therefore the fine grain strengthening contributes more to the strength of the thin end than the thick end. FIGS. 3-4 are distribution plots of the precipitates at the thin end and the thick end of the steel sheet of example 3, illustrating that the precipitates at the thin end of the steel sheet are larger in size than the thick end and are fewer in number than the thick end, so that the precipitation strengthening contributes less to the strength of the thin end than the thick end. Under the combined action of the two strengthening mechanisms, the strength distribution of the steel in the length direction has good uniformity.
Claims (6)
1. The longitudinal variable-thickness ultrahigh-strength ship board is characterized in that the steel board comprises the following chemical components in percentage by weight: 0.060% -0.120% of C, 0.15% -0.50% of Si, 1.10% -1.70% of Mn, 0.040% -0.070% of V, 0.20% -0.50% of Cu, 0.10% -0.50% of Ni, 0.005% -0.020% of Ti, 0.0120% -0.0180% of N, less than or equal to 0.010% of P, less than or equal to 0.005% of S, 0.015% -0.030% of Als, and the balance of Fe and inevitable impurities.
2. The longitudinally thickened ultrahigh-strength ship board as claimed in claim 1, wherein the yield strength of the steel board is more than 460MPa, the elongation after fracture is more than 25.0%, the impact energy absorption at-40 ℃ is more than 150J, the impact energy absorption at-60 ℃ is more than 100J, the impact performance at-40 ℃ is more than 110J, and the impact performance at-60 ℃ is more than 80J.
3. The longitudinally-thickened ultrahigh-strength ship board as claimed in claim 1, wherein the strength difference between the maximum thickness and the minimum thickness of the steel board is within 15MPa, and the toughness and the plasticity are consistent.
4. A method for producing a longitudinally thickened ultrahigh-strength ship plate according to any one of claims 1 to 3, which comprises smelting, continuous casting, heating by a heating furnace and rolling, and is characterized in that:
(1) the steel with the components is smelted, and the smelting process route is as follows: the method comprises the following steps of molten iron pretreatment, converter smelting, LF-RH continuous casting, and nitrogen blowing treatment in a converter or RH to control the nitrogen content in smelting steel;
(2) continuously casting the molten steel obtained in the step (1) to prepare a continuous casting billet, and controlling the superheat degree of a tundish to be 20-30 ℃;
(3) heating the casting blank obtained in the step (2) to 1130-1250 ℃, and preserving heat for 40-240 min;
(4) rolling of
a) A rough rolling stage: rolling the heated casting blank at the casting blank starting temperature of 1040-1120 ℃, rolling the casting blank to the thickness of 2.0-3.0 times of the maximum thickness of the final steel plate, and obtaining an intermediate blank after rolling;
b) and (3) intermediate rolling stage: the intermediate blank obtained in the step a) is heated to 850-910 ℃ and then is rolled until the rolling thickness is 1.5-2.0 times of the maximum thickness of the final steel plate;
c) and (3) finish rolling stage: rolling by variable thickness according to the required thickness and inclination, and controlling the final rolling temperature of the steel plate to be 800-850 ℃;
(5) carrying out accelerated cooling on the rolled steel plate, wherein the start cooling temperature is 700-780 ℃, and the re-reddening temperature is 550-720 ℃;
(6) and (5) air-cooling the steel plate obtained in the step (5) to room temperature to obtain a final longitudinal thickness-variable steel plate.
5. The method for producing a longitudinally thickened ultrahigh-strength ship board according to claim 4, wherein: the converter or RH nitrogen blowing treatment time in the step (1) is more than or equal to 10 min.
6. The method for producing a longitudinally thickened ultrahigh-strength ship board according to claim 4, wherein: the finishing temperature, the start cooling temperature and the re-reddening temperature are set according to the thickness of the steel plate
The temperature of (a) is controlled, wherein: t is tmaxMaximum thickness of the final steel sheet, tminThe minimum thickness of the final steel sheet.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010929332.3A CN111996462B (en) | 2020-09-07 | 2020-09-07 | Longitudinal variable-thickness ultrahigh-strength ship board and production method thereof |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010929332.3A CN111996462B (en) | 2020-09-07 | 2020-09-07 | Longitudinal variable-thickness ultrahigh-strength ship board and production method thereof |
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| Publication Number | Publication Date |
|---|---|
| CN111996462A true CN111996462A (en) | 2020-11-27 |
| CN111996462B CN111996462B (en) | 2022-02-18 |
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