CN112609125A - 380 MPa-grade steel for automobile structure and production method thereof - Google Patents

380 MPa-grade steel for automobile structure and production method thereof Download PDF

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CN112609125A
CN112609125A CN202011252585.8A CN202011252585A CN112609125A CN 112609125 A CN112609125 A CN 112609125A CN 202011252585 A CN202011252585 A CN 202011252585A CN 112609125 A CN112609125 A CN 112609125A
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finishing mill
steel
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temperature
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CN112609125B (en
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孙成钱
时晓光
董毅
刘仁东
徐荣杰
王俊雄
韩楚菲
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Angang Steel Co Ltd
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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
    • B21B45/00—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills
    • B21B45/02—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills for lubricating, cooling, or cleaning
    • B21B45/0203—Cooling
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C33/00—Making ferrous alloys
    • C22C33/04—Making ferrous alloys by melting
    • 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
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • 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
    • 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
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • 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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/20—Ferrous alloys, e.g. steel alloys containing chromium with copper
    • 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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/24—Ferrous alloys, e.g. steel alloys containing chromium with vanadium
    • 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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/26—Ferrous alloys, e.g. steel alloys containing chromium with niobium or tantalum
    • 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
    • C22C38/60—Ferrous alloys, e.g. steel alloys containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/005—Ferrite
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/009—Pearlite

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Heat Treatment Of Sheet Steel (AREA)

Abstract

The invention relates to 380 MPa-grade steel for an automobile structure and a production method thereof, wherein the steel for the structure comprises the following chemical components in percentage by mass: c: 0.050% -0.070%, Si: 0.02% -0.10%, Mn: 0.70% -1.05%, Al: 0.020% -0.040%, Nb: 0.015% -0.025%, V: 0.010-0.025%, Cr: 0.10-0.25%, Cu: 0.32-0.52%, Sb: 0.044-0.064%, Bi: 0.011-0.044%, P is less than or equal to 0.015%, S is less than or equal to 0.006%, and the balance is Fe and inevitable impurities. The advantages are that: the invention has excellent mechanical property and corrosion resistance and is used for steel for automobile structures.

Description

380 MPa-grade steel for automobile structure and production method thereof
Technical Field
The invention belongs to the field of production of steel for automobile structures, and particularly relates to 380 MPa-grade steel for automobile structures and a production method thereof.
Background
With the rapid development of the automobile industry and the transportation industry in China, the demand of large-tonnage trucks is particularly increased continuously, the purposes of reducing the weight of automobile structural parts to reduce the self weight, saving energy, reducing environmental pollution and improving carrying efficiency are achieved, and the application of high-performance and high-surface-quality hot-rolled automobile steel plates is promoted. The modern automobile industry generally adopts the protection measures for the corrosion of the steel plate to plate zinc on the surface of the steel plate or brush coating anti-corrosion paint, and the automobile steel plate does not have the anti-corrosion performance. Once the anticorrosive coating falls off, the steel plate can be corroded rapidly, so that the steel plate is invalid in use, and the anticorrosive coating can pollute the environment and destroy the ecological environment. Therefore, the hot-rolled steel for automobile structure, which has high corrosion resistance and high surface quality, has improved service life and can occupy the domestic market of steel for automobile structure, has been developed.
The steel plate with yield strength more than or equal to 380MPa, tensile strength more than or equal to 480MPa and transverse elongation A more than or equal to 35% is applied in the steel plate for the automobile structure. In the prior art, Chinese patent application with publication number CN 107641762A discloses a 340 MPa-grade hot-rolled automobile structural steel plate with excellent cold-forming performance and a manufacturing method thereof, the hot-rolled steel plate is produced by adding a certain amount of Nb and Ti into a common C-Mn component system, S, N in steel is fixed by using a small amount of Ti, the fine-grain effect of Nb is fully exerted, but the elongation of the steel plate is up to 32%, the steel plate does not meet the requirement of high-forming automobile parts, and the steel plate has no corrosion resistance.
The Chinese patent application with publication number CN 107723607A discloses a 420 MPa-grade hot-rolled automobile structural steel plate with excellent cold-forming performance and a manufacturing method thereof, a hot-rolled steel plate produced by adding a certain amount of Nb and Ti is designed by utilizing a common C-Mn component system, S, N in steel is fixed by utilizing trace Ti, the fine grain function of Nb is fully exerted, but the elongation of the steel plate is up to 25 percent, the steel plate does not meet the requirement of high-forming automobile parts, and the steel plate has no corrosion resistance.
Chinese patent application with publication number CN 105369134B discloses a 400 MPa-grade acid-washing-free hot rolled steel plate for an automobile structure and a production method thereof, the hot rolled steel plate is designed by a common C-Mn component system, the strength is improved by solid solution strengthening of carbon and manganese elements, but the yield strength of the steel plate is 311MPa at most, the steel plate does not meet the requirement of high-strength formed automobile parts, and the steel plate has no corrosion resistance.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention aims to provide 380 MPa-grade steel for automobile structures and a production method thereof, the steel plate has the yield strength of more than or equal to 380MPa, the tensile strength of more than or equal to 480MPa and the transverse elongation A of more than or equal to 35 percent, has the anticorrosion performance, and meets the production requirement of high-strength formed automobile parts.
In order to achieve the purpose, the invention is realized by the following technical scheme:
the 380 MPa-grade steel for the automobile structure comprises the following chemical components in percentage by mass:
c: 0.050% -0.070%, Si: 0.02% -0.10%, Mn: 0.70% -1.05%, Al: 0.020% -0.040%, Nb: 0.015% -0.025%, V: 0.010-0.025%, Cr: 0.10-0.25%, Cu: 0.32-0.52%, Sb: 0.044-0.064%, Bi: 0.011-0.044%, P is limited to be less than or equal to 0.015%, S is limited to be less than or equal to 0.006%, and the balance is Fe and inevitable impurities; 30-40 percent of ferrite, 58-68 percent of pearlite and 1-2 percent of bainite by volume.
Wherein, the main functions of the chemical components are as follows:
c: carbon is the most important solid solution strengthening element in steel and guarantees the strength of the steel. In view of excellent cold press formability and weldability and dimensional stability after cold pressing, the carbon content cannot be excessively high, and too low a carbon content does not exert a solid solution strengthening effect, so that the optimum range of carbon is selected to be 0.050% to 0.070%.
Si: silicon is a solid-solution strengthening element and can contribute to the strength of the steel sheet. However, too high a silicon in the steel affects the hot rolled surface quality. Therefore, the content of silicon is selected to be 0.020% to 0.10%.
Mn: manganese can form a substitutional solid solution in steel, so that a strong solid solution strengthening effect is achieved, the yield strength and the tensile strength are linearly increased, the steel strength is increased within a certain range, the plasticity and the toughness of the steel are hardly reduced, and the carbon equivalent of the steel can be increased due to the excessively high manganese content. Therefore, the manganese content is selected to be 0.70-1.05%.
Al: al is a common deoxidizer in steel, a small amount of Al is added into the steel, AlN can be precipitated to play a role in refining grains to a certain extent, the Al also has the oxidation resistance and the corrosion resistance, the combination of the Al, Cr and Si can obviously improve the high-temperature non-peeling performance of the steel and the surface quality of a steel plate, and the Al is too high and is easy to form oxide inclusions, so the content of the Al is limited to 0.020-0.040%.
P: phosphorus increases the temperature at which the alpha phase is formed, and expands the temperature range over which the alpha phase is formed. However, the content of phosphorus is too high, which deteriorates the workability of the steel sheet, and is limited to 0.015% for obtaining a high elongation.
S: since sulfur forms sulfide inclusions such as MnS and becomes a starting point of cracks to deteriorate workability, the content is preferably as small as 0.006%.
Nb: niobium can effectively delay recrystallization of deformed austenite, prevent austenite grains from growing, increase austenite recrystallization temperature, refine grains and improve strength and toughness of steel, and is a strong carbon and nitride forming element which can be combined with carbon and nitrogen to form stable and fine carbon and nitride to play a significant precipitation strengthening role, and the addition of Nb increases recrystallization termination temperature, so that the finish rolling temperature can be carried out at a higher temperature, and the load of a rolling mill is reduced, therefore, the optimal range of the niobium content is selected to be between 0.015 and 0.025 percent.
V: is a strong carbide forming element, and adds a trace amount of V into steel, so that the formed VC can prevent austenite grains from excessively growing when a steel billet is heated, thereby achieving the purpose of refining the original austenite grains. Since V can also exist in the form of second phase particles in steel and acts as precipitation strengthening, the amount of V is selected to be 0.010% to 0.025%.
Cr: is a carbide forming element, can delay pearlite transformation and improve the hardenability of the steel. Thereby being beneficial to the formation of bainite structure, refining the structure and playing a role in strengthening. If the chromium content is too high, the workability and formability of the material will be deteriorated. The chromium content is selected in such a way that the formation of bainite is promoted, and is therefore selected in the range from 0.10% to 0.25%.
Cu: the copper element can enlarge an austenite phase region, improve the weather resistance of steel, improve the weldability of the steel and effectively improve the corrosion resistance of the steel, but causes hot brittleness when the Cu content is high, the surface performance of the steel plate is deteriorated, in addition, the copper element is beneficial to the strength and the hot workability of the steel plate under a certain Cu content, the hot rolling edge crack tendency of the steel plate is effectively reduced, and the surface quality of the steel plate is obviously improved. Cu also has the effect of reducing work hardening and improving the plasticity of the steel sheet. Therefore, the copper content is selected to be 0.32% to 0.52%.
Sb: the antimony element is mainly distributed in the crystal boundary and the crystal grain in the steel, so that the strength of the steel plate is improved, the diffusion rate of elements such as carbon, oxygen and the like on the crystal boundary is reduced, the decarburization and the oxidation phenomena are reduced, the surface and the mechanical property of the steel plate are improved, and the addition of the antimony can promote the surface of a steel plate matrix to form a uniform and compact oxide film (rich in elements such as Sb, Cu, Cr and the like), so that the moisture and oxygen in the air can be effectively prevented from continuously entering the matrix to form a corrosive internal environment, the corrosion resistance of the matrix is improved, and the corrosion. Therefore, the Sb content is limited to 0.044% to 0.064%.
Bi: the bismuth is mainly distributed in the crystal boundary and the crystal grain in the steel, so that the strength of the steel plate is improved, the diffusion rate of elements such as carbon, oxygen and the like on the crystal boundary is reduced, the decarburization and the oxidation phenomena are reduced, and the surface and the mechanical property of the steel plate are improved. Therefore, the Bi content is limited to 0.011% to 0.044%.
A production method of 380 MPa-level steel for automobile structures comprises smelting, heating and rolling processes, wherein the rolling process adopts 6 racks for finish rolling production, and the specific production method comprises the following steps:
1) a heating process: directly hot-charging (170) 230 mm thick x (1550-1880) mm wide continuous casting slabs into a heating furnace for heating, wherein the hot charging temperature is more than 750 ℃, the preheating section is preheated at the furnace gas temperature of 800-1000 ℃, the preheating time is 25-30 min, the temperatures of the heating 1 section and the heating 2 section are respectively controlled at 1120-1200 ℃ and 1210-1240 ℃, the total soaking time of the heating 1 section and the heating 2 section is 15-20 min, the temperature of the heating 1 section is 1220-1240 ℃, the soaking time is 65-110 min, the furnace pressure is in a micro-positive pressure state, and the positive pressure value is controlled at 3-15 Pa;
2) the rolling process comprises the following steps: the rough rolling adopts 6-pass rolling and 3-pass descaling processes, the first rough rolling mill R1 descales 1, 3 and 5 passes, the high-pressure water outlet pressure is 21-30 MPa, the rough rolling outlet temperature is 1050-1100 ℃, the thickness of the intermediate blank is 30-40 mm, the width is 1550-1880 mm, the intermediate blank is insulated by a heat-insulating cover before entering a hot rolling finishing mill group, the finish rolling is 6-stand continuous rolling, the high-pressure water descaling is carried out before the finish rolling, the finish rolling inlet temperature is not higher than 1060 ℃, the finish rolling temperature is 840-; meanwhile, the F5 and F6 racks are descaled by adopting high water pressure of 21-30 MPa, and cooling water in the rest racks is completely opened; the convexity control precision of the steel plate is +/-13 mu m, the flatness is controlled within 25I, the thickness control precision is +/-25 mu m, and the thickness of a finished product is 3-10 mm.
In the step 2), the finish rolling adopts high-tension rolling: the tension between the frames of the first frame finishing mill F1 and the second frame finishing mill F2 is controlled to be 7-14N/mm2The tension between the frames of the second finishing mill F2 and the third finishing mill F3 is controlled to be 13-22N/mm2The tension between the stands of the third finishing mill F3 and the fourth finishing mill F4 is controlled to be 13-20N/mm2The tension between the stands of the fourth finishing mill F4 and the fifth finishing mill F5 is controlled to be 8-18N/mm2The tension between the frames of the fifth finishing mill F5 and the sixth finishing mill F6 is controlled to be 6-12N/mm2。
The method also comprises a cooling process: and after the final rolling, adopting front-section rapid continuous laminar cooling, wherein the cooling rate is 18-35 ℃/s.
Further comprising a coiling temperature: the coiling temperature is 560-630 ℃.
Compared with the prior art, the invention has the beneficial effects that:
1. the addition of Nb increases the recrystallization termination temperature, so that the finish rolling temperature can be carried out at a higher temperature, and the load of a rolling mill is reduced;
2. the addition of Cu expands an austenite phase region, improves the weather resistance of steel, improves the weldability of steel and can also effectively improve the corrosion resistance of steel;
3. the addition of Sb can reduce the diffusion rate of elements such as carbon, oxygen and the like on a crystal boundary, reduce the phenomena of decarburization and oxidation, improve the surface and the mechanical property of the steel plate, and promote the surface of a steel plate matrix to form a layer of uniform and compact oxide film (rich in elements such as Sb, Cu, Cr and the like) by the addition of Sb, so that air moisture and oxygen can be effectively prevented from continuously entering the matrix to form a corrosive internal environment, the corrosion resistance of the matrix is improved, and the corrosion resistance of the steel plate is enhanced;
4. bi: the bismuth is mainly distributed in the crystal boundary and the crystal grain in the steel, so that the strength of the steel plate is improved, the diffusion rate of elements such as carbon, oxygen and the like on the crystal boundary is reduced, the decarburization and the oxidation phenomena are reduced, and the surface and the mechanical property of the steel plate are improved.
5. And a front-section rapid continuous cooling process is adopted after rolling, so that the generation of a band-shaped structure in a steel plate is avoided.
6. The invention has excellent mechanical property and corrosion resistance, is used for steel for automobile structures, and has yield strength of more than or equal to 380MPa, tensile strength of more than or equal to 480MPa and transverse elongation A of more than or equal to 35 percent.
Detailed Description
The present invention is described in detail below, but it should be noted that the practice of the present invention is not limited to the following embodiments.
The 380 MPa-grade steel for the automobile structure comprises the following chemical components in percentage by mass:
c: 0.050% -0.070%, Si: 0.02% -0.10%, Mn: 0.70% -1.05%, Al: 0.020% -0.040%, Nb: 0.015% -0.025%, V: 0.010-0.025%, Cr: 0.10-0.25%, Cu: 0.32-0.52%, Sb: 0.044-0.064%, Bi: 0.011-0.044%, P is less than or equal to 0.015%, S is less than or equal to 0.006%, and the balance is Fe and inevitable impurities. The volume percentage of ferrite in the final structure is 30-40%, the volume percentage of pearlite is 58-68%, and the volume percentage of bainite is 1-2%. The yield strength is more than or equal to 380MPa, the tensile strength is more than or equal to 480MPa, and the transverse elongation A is more than or equal to 35 percent.
The production method of the 380 MPa-grade steel for the automobile structure adopts the chemical components, adopts 6 frames to carry out finish rolling through smelting, heating and rolling procedures to produce the steel for the automobile structure, and comprises the following steps:
(1) a heating process: directly hot-charging a (170) -230 mm thick x (1550-1880) mm wide continuous casting plate blank into a stepping heating furnace for heating, wherein the hot-charging temperature is more than 750 ℃, the preheating section is rapidly preheated at a furnace gas temperature of 800-1000 ℃ for 25-30 min, the temperatures of the heating 1 section and the heating 2 section are respectively controlled at 1120-1200 ℃ and 1210-1240 ℃, the heating time is 15-20 min (the total heating time of the heating 1 section and the heating 2 section), the temperature of the soaking section is 1220-1240 ℃, the soaking time is 65-110 min, the furnace pressure is in a micro-positive pressure state (the pressure value is 3-15 Pa), and the oxidation burning loss is reduced. The proper heating temperature and the proper heat preservation time enable alloy elements in the plate blank to be completely dissolved in solid solution and the plate blank components to be uniform, and the effects of controlling the size of original austenite grains, saving energy and the like are achieved.
(2) The rolling process comprises the following steps: the rough rolling adopts 6-pass rolling and 3-pass descaling processes, the first rough rolling mill R1 descales 1, 3 and 5 passes, an upper row of water spray headers and a lower row of water spray headers of a descaling box are opened simultaneously, the pressure of a high-pressure water outlet is 21-30 MPa, the temperature of the rough rolling outlet is 1050-1100 ℃, the thickness of an intermediate blank is 30-40 mm, the width of the intermediate blank is 1550-1880 mm, the intermediate blank is insulated by a heat insulation cover before entering a hot rolling finishing mill set, the temperature drop of the intermediate blank on a delay roller way and the temperature difference of the head, the tail and the plate width direction are reduced, the finish rolling is 6-rack continuous rolling, the high-pressure water descaling is performed before the finish rolling, the finish rolling inlet temperatureThe finish rolling is carried out at 0 ℃ by adopting high-tension rolling, and the tension between the frames of a first finishing mill F1 and a second finishing mill F2 is controlled to be 7-14N/mm2The tension between the frames of the second finishing mill F2 and the third finishing mill F3 is controlled to be 13-22N/mm2The tension between the stands of the third finishing mill F3 and the fourth finishing mill F4 is controlled to be 13-20N/mm 2, and the tension between the stands of the fourth finishing mill F4 and the fifth finishing mill F5 is controlled to be 8-18N/mm2The tension between the frames of the fifth finishing mill F5 and the sixth finishing mill F6 is controlled to be 6-12N/mm2Meanwhile, the F5 and F6 racks are descaled by adopting high water pressure of 21-30 MPa, and cooling water in the rest racks is completely opened; the convexity control precision of the steel plate is +/-13 mu m, the flatness is controlled within 25I, the thickness control precision is +/-25 mu m, and the thickness of a finished product is 3-10 mm.
(3) And (3) a cooling process: and after the final rolling, adopting front-section rapid continuous laminar cooling, wherein the cooling rate is 18-35 ℃/s. The continuous laminar cooling process makes bainite precipitate fast in great amount, and this can inhibit the growth of crystal grains and ensure the bainite content, so as to refine the bainite crystal grains.
(4) Coiling temperature: the coiling temperature is 560-630 ℃. The coiling temperature is too high, so that the strength of the steel plate is insufficient, the elongation is reduced due to too low coiling temperature, the second phase particles can be fully precipitated after the steel plate is coiled in a temperature range, and the plasticity is good.
Examples
The specific components, temperature system, finishing tension control parameters, properties of the steel sheet and the percentage of the structure volume of 6 examples of the invention are shown in tables 1 to 5.
TABLE 1 chemical composition of inventive examples (wt%)
Figure BDA0002772066530000061
TABLE 2 Hot Rolling temperature System of examples of the present invention
Figure BDA0002772066530000071
TABLE 3 finishing tension control parameters of examples of the present invention
Figure BDA0002772066530000072
TABLE 4 mechanical Property parameters of the examples of the invention
Figure BDA0002772066530000073
Figure BDA0002772066530000081
TABLE 5 percentage of tissue volume in the examples of the invention
Numbering Ferrite Pearlite Bainite for treating cancer
Example 1 38％ 60％ 2％
Example 2 30％ 68％ 2％
Example 3 33％ 66％ 1％
Example 4 35％ 63％ 2％
Example 5 40％ 58％ 2％
Example 6 39％ 60％ 1％
。

Claims (5)

1. The steel for the 380 MPa-grade automobile structure is characterized by comprising the following chemical components in percentage by mass:
c: 0.050% -0.070%, Si: 0.02% -0.10%, Mn: 0.70% -1.05%, Al: 0.020% -0.040%, Nb: 0.015% -0.025%, V: 0.010-0.025%, Cr: 0.10-0.25%, Cu: 0.32-0.52%, Sb: 0.044-0.064%, Bi: 0.011-0.044%, P is limited to be less than or equal to 0.015%, S is limited to be less than or equal to 0.006%, and the balance is Fe and inevitable impurities; 30-40 percent of ferrite, 58-68 percent of pearlite and 1-2 percent of bainite by volume.
2. The production method of 380 MPa-grade steel for automobile structures according to claim 1, wherein the production method comprises the following steps of smelting, heating and rolling, and the rolling process adopts 6 stands for finish rolling production:
1) a heating process: directly hot-charging (170) 230 mm thick x (1550-1880) mm wide continuous casting slabs into a heating furnace for heating, wherein the hot charging temperature is more than 750 ℃, the preheating section is preheated at the furnace gas temperature of 800-1000 ℃, the preheating time is 25-30 min, the temperatures of the heating 1 section and the heating 2 section are respectively controlled at 1120-1200 ℃ and 1210-1240 ℃, the total soaking time of the heating 1 section and the heating 2 section is 15-20 min, the temperature of the heating 1 section is 1220-1240 ℃, the soaking time is 65-110 min, the furnace pressure is in a micro-positive pressure state, and the positive pressure value is controlled at 3-15 Pa;
2) the rolling process comprises the following steps: the rough rolling adopts 6-pass rolling and 3-pass descaling processes, the first rough rolling mill R1 descales 1, 3 and 5 passes, the high-pressure water outlet pressure is 21-30 MPa, the rough rolling outlet temperature is 1050-1100 ℃, the thickness of the intermediate blank is 30-40 mm, the width is 1550-1880 mm, the intermediate blank is insulated by a heat-insulating cover before entering a hot rolling finishing mill group, the finish rolling is 6-stand continuous rolling, the high-pressure water descaling is carried out before the finish rolling, the finish rolling inlet temperature is not higher than 1060 ℃, the finish rolling temperature is 840-; meanwhile, the F5 and F6 racks are descaled by adopting high water pressure of 21-30 MPa, and cooling water in the rest racks is completely opened; the convexity control precision of the steel plate is +/-13 mu m, the flatness is controlled within 25I, the thickness control precision is +/-25 mu m, and the thickness of a finished product is 3-10 mm.
3. The method for producing a steel for an automobile structure of 380MPa grade according to claim 2, wherein in the step 2), the finish rolling is performed by high tension rolling: the tension between the frames of the first frame finishing mill F1 and the second frame finishing mill F2 is controlled to be 7-14N/mm2The tension between the frames of the second finishing mill F2 and the third finishing mill F3 is controlled to be 13-22N/mm2The tension between the stands of the third finishing mill F3 and the fourth finishing mill F4 is controlled to be 13-20N/mm2A tension between the stands of the fourth finishing mill F4 and the fifth finishing mill F5Controlling the force at 8-18N/mm2The tension between the frames of the fifth finishing mill F5 and the sixth finishing mill F6 is controlled to be 6-12N/mm2。
4. The production method of 380MPa grade steel for automobile structures according to claim 2, further comprising a cooling process: and after the final rolling, adopting front-section rapid continuous laminar cooling, wherein the cooling rate is 18-35 ℃/s.
5. The production method of 380MPa grade steel for automobile structures according to claim 2, further comprising the following coiling temperature: the coiling temperature is 560-630 ℃.
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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102912229A (en) * 2012-10-23 2013-02-06 鞍钢股份有限公司 390MPa-grade low-cost hot rolling structural steel plate and manufacture method thereof
CN108504958A (en) * 2018-05-15 2018-09-07 首钢集团有限公司 A kind of 690MPa grades of hot rolling think gauge low yield strength ratio automobile spoke steel and preparation method thereof
CN109082595A (en) * 2018-09-04 2018-12-25 鞍钢股份有限公司 A kind of buried structural steel of alkaline soil corrosion-resistant and its manufacturing method
CN109082594A (en) * 2018-09-04 2018-12-25 鞍钢股份有限公司 A kind of buried structural steel of acid resistance soil corrosion and its manufacturing method
CN110669914A (en) * 2019-09-30 2020-01-10 鞍钢股份有限公司 High-strength steel for automobile axle housing for cold stamping and production method thereof
CN110669989A (en) * 2019-09-30 2020-01-10 鞍钢股份有限公司 High-elongation steel for automobile axle housing for cold stamping and production method thereof
CN111902553A (en) * 2018-03-30 2020-11-06 日本制铁株式会社 Steel sheet and method for producing same

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102912229A (en) * 2012-10-23 2013-02-06 鞍钢股份有限公司 390MPa-grade low-cost hot rolling structural steel plate and manufacture method thereof
CN111902553A (en) * 2018-03-30 2020-11-06 日本制铁株式会社 Steel sheet and method for producing same
CN108504958A (en) * 2018-05-15 2018-09-07 首钢集团有限公司 A kind of 690MPa grades of hot rolling think gauge low yield strength ratio automobile spoke steel and preparation method thereof
CN109082595A (en) * 2018-09-04 2018-12-25 鞍钢股份有限公司 A kind of buried structural steel of alkaline soil corrosion-resistant and its manufacturing method
CN109082594A (en) * 2018-09-04 2018-12-25 鞍钢股份有限公司 A kind of buried structural steel of acid resistance soil corrosion and its manufacturing method
CN110669914A (en) * 2019-09-30 2020-01-10 鞍钢股份有限公司 High-strength steel for automobile axle housing for cold stamping and production method thereof
CN110669989A (en) * 2019-09-30 2020-01-10 鞍钢股份有限公司 High-elongation steel for automobile axle housing for cold stamping and production method thereof

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