CN117187682B - 1200MPa battery pack steel for new energy automobile and preparation method thereof - Google Patents
1200MPa battery pack steel for new energy automobile and preparation method thereof Download PDFInfo
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- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 69
- 239000010959 steel Substances 0.000 title claims abstract description 69
- 238000002360 preparation method Methods 0.000 title abstract description 9
- 238000005097 cold rolling Methods 0.000 claims abstract description 16
- 238000005098 hot rolling Methods 0.000 claims abstract description 12
- 238000009749 continuous casting Methods 0.000 claims abstract description 9
- 238000003723 Smelting Methods 0.000 claims abstract description 6
- 238000005554 pickling Methods 0.000 claims abstract description 6
- 239000012535 impurity Substances 0.000 claims abstract description 5
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 4
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 4
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 4
- 229910052717 sulfur Inorganic materials 0.000 claims abstract description 4
- 229910052750 molybdenum Inorganic materials 0.000 claims abstract description 3
- 238000001816 cooling Methods 0.000 claims description 22
- 229910000859 α-Fe Inorganic materials 0.000 claims description 16
- 229910000734 martensite Inorganic materials 0.000 claims description 13
- 238000000034 method Methods 0.000 claims description 13
- 238000010438 heat treatment Methods 0.000 claims description 10
- 238000005275 alloying Methods 0.000 claims description 9
- 230000008569 process Effects 0.000 claims description 9
- 238000005096 rolling process Methods 0.000 claims description 9
- 238000000137 annealing Methods 0.000 claims description 7
- 238000010583 slow cooling Methods 0.000 claims description 7
- 239000002253 acid Substances 0.000 claims description 6
- 150000001247 metal acetylides Chemical class 0.000 claims description 6
- 230000009467 reduction Effects 0.000 claims description 6
- 238000005406 washing Methods 0.000 claims description 6
- 238000010791 quenching Methods 0.000 claims description 5
- 230000000171 quenching effect Effects 0.000 claims description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 4
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims description 3
- 238000005266 casting Methods 0.000 claims description 3
- 238000005246 galvanizing Methods 0.000 claims description 3
- 238000003303 reheating Methods 0.000 claims description 3
- 229910052725 zinc Inorganic materials 0.000 claims description 3
- 239000011701 zinc Substances 0.000 claims description 3
- 229910001566 austenite Inorganic materials 0.000 description 9
- 230000000694 effects Effects 0.000 description 7
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 5
- 238000001556 precipitation Methods 0.000 description 5
- 238000005728 strengthening Methods 0.000 description 5
- 229910000885 Dual-phase steel Inorganic materials 0.000 description 4
- 229910052799 carbon Inorganic materials 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 230000003647 oxidation Effects 0.000 description 4
- 238000007254 oxidation reaction Methods 0.000 description 4
- 239000006104 solid solution Substances 0.000 description 4
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- 238000005336 cracking Methods 0.000 description 3
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 230000000996 additive effect Effects 0.000 description 2
- 229910001563 bainite Inorganic materials 0.000 description 2
- 239000010960 cold rolled steel Substances 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 229910001562 pearlite Inorganic materials 0.000 description 2
- 238000007747 plating Methods 0.000 description 2
- 230000009466 transformation Effects 0.000 description 2
- 206010016654 Fibrosis Diseases 0.000 description 1
- 229910001335 Galvanized steel Inorganic materials 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 229910000797 Ultra-high-strength steel Inorganic materials 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
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- 125000004429 atom Chemical group 0.000 description 1
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Classifications
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
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Abstract
The invention provides a 1200MPa battery pack steel for a new energy automobile and a preparation method thereof, wherein the steel comprises the following ：C：0.20％～0.24％,Si：0.20％～0.40％,Al：0.40％～0.60％,Mn：0.9％～1.1％,Cr：0.30％～0.60％,Mo：0.20％～0.40％,B：0.004％～0.006％,P≤0.015％,S≤0.003％,Ti：0.015～0.035％, weight percent of Fe and unavoidable impurities in balance; the preparation method comprises smelting, continuous casting, hot rolling, pickling, cold rolling, continuous deplating and finishing; the tensile strength of the steel for the battery pack, which is produced by the invention, is more than 1200MPa, the yield strength is 900-1050 MPa, the elongation is more than or equal to 12%, the hole expansion rate is more than or equal to 55%, the isothermal 5min yield attenuation at 400 ℃ is less than 200MPa, and the isothermal 5min yield attenuation at 800 ℃ is less than 500MPa.
Description
Technical Field
The invention belongs to the field of metal materials, and particularly relates to 1200MPa battery pack steel for a new energy automobile and a preparation method thereof.
Background
The battery pack is composed of an upper cover plate, a cross beam, a frame and a lower plate, wherein the cross beam and the frame are used for guaranteeing the safety of the battery pack, guaranteeing the mounting strength of the module, effectively resisting side impact and guaranteeing the safety of the module in the battery. Thus, the cross beams and frames require high strength steel or ultra high strength steel for the selection of materials. At present, the steel for the cross beam and the frame is mainly based on traditional high-strength steel, such as high-strength dual-phase steel, complex-phase steel, martensitic steel, quenching and distributing steel and the like.
The Chinese patent with the application number 2018115042560 discloses a high-N content ultrafine grain 1200MPa cold-rolled dual-phase steel and a production process ,C：0.14％～0.17％,Si：0.2％～0.3％,Mn：1.5％～2.0％,P≤0.015％,S≤0.010％,V：0.10％～0.15％,Cr：0.03％～0.04％,Als：0.02～0.03％,Ti：0.03～0.06％,N:0.012％～0.018％, thereof, and the balance of Fe and unavoidable impurities. The steel plate with the tensile strength of 1200MPa grade is obtained, but the steel is added with high N content, so that the smelting cost is greatly increased. And the yield strength is too low in performance, and the application working conditions of the steel for battery packs such as the cross beam, the frame and the like can not be born.
Publication number CN109280857A discloses a 1200MPa grade ultra-fast cold-rolled dual-phase steel plate and a preparation method thereof, and the disclosed dual-phase steel comprises the following main chemical components: c:0.12 to 0.17 percent, si:0.3 to 0.6 percent, mn:2.0 to 2.4 percent, P is less than or equal to 0.015 percent, S is less than or equal to 0.008 percent, als:0.03 to 0.06 percent of Ti:0.03 to 0.06 percent, N is less than or equal to 0.005 percent, and the balance is Fe and unavoidable impurities. The steel has the following properties: yield strength is 820-950 MPa, tensile strength: 1200-1350 MPa, and the elongation is 5-10%. The preparation method of the steel involves ultra-rapid cooling of 130-150 ℃/s, which is difficult to realize in a practical production process, and the drawing performance of the product is difficult to meet the requirement of forming more complicated parts.
Disclosure of Invention
The invention aims to overcome the problems and the shortcomings and provide the 1200MPa battery pack steel for the new energy automobile, which has high-temperature tensile property and excellent steel plate softening resistance under simulated fire conditions, and the preparation method thereof.
The invention aims at realizing the following steps:
The 1200MPa battery pack steel for the new energy automobile comprises the following ：C：0.20％～0.24％,Si：0.20％～0.40％,Al：0.40％～0.60％,Mn：0.9％～1.1％,Cr：0.30％～0.60％,Mo：0.20％～0.40％,B：0.004％～0.006％,P≤0.015％,S≤0.003％,Ti：0.015～0.035％, parts by weight of Fe and unavoidable impurities as the balance. Preferably, C+Mn/6 is more than or equal to 0.36 and less than or equal to 0.4 in the 1200MPa battery pack steel.
The steel microstructure for the battery pack comprises critical zone ferrite, epitaxial ferrite, tempered martensite, carbide and other small amounts of unidentified phases, wherein each microstructure comprises the following components in percentage by volume: 8-12% of ferrite in a critical area, 10-15% of epitaxial ferrite, 70-75% of tempered martensite and 2.2-3.5% of carbide; preferably, the carbide is mainly theta-type carbide, the volume fraction of the theta-type carbide is more than 70% of all carbides, and the average grain size is 45-80 nm.
The tensile strength of the steel for the battery pack is more than 1200MPa, the yield strength is 900-1050 MPa, the elongation is more than or equal to 12%, the hole expansion rate is more than or equal to 55%, the isothermal 5-min yield attenuation at 400 ℃ is less than 200MPa, and the isothermal 5-min yield attenuation at 800 ℃ is less than 500MPa.
The reason for designing the components of the invention is as follows:
c: the C element high-strength steel is added with elements, so that the strength of the steel plate is ensured. In the invention, the addition range of C is strictly controlled, and the addition of C ensures the C behavior in tempered martensite, and the content and grain size of theta-type carbide.
Si: the Si element is a conventional solid solution strengthening element and plays a role in strengthening a matrix. The Si element has the main function of inhibiting carbide precipitation in tempered martensite to a certain extent and controlling carbide content among tempered martensite. The invention adopts a low Si design, because the surface quality of the cold-rolled steel plate is effectively controlled, the surface of the steel plate is obviously affected by the high Si addition, and an internal oxidation layer and a grain boundary oxidation layer are formed; in addition, the excessive addition of Si also seriously affects the surface quality of the galvanized steel sheet, and forms a phenomenon of 'skip plating'.
Mn: mn is a conventional strengthening element in steel, and the high-strength steel component system mainly comprises a C-Mn system. The invention is characterized in that a low Mn design is adopted, and the reason is that the Mn content is more than 1000MPa and 2.0 percent or even more than 1000MPa is added conventionally, so that the hardenability of the steel plate is obviously improved, bainite and martensite are formed in the hot coiling stage, and the cold rolling difficulty is seriously increased; furthermore, C, mn composite addition is easy to cause C/Mn segregation to cause excessive high edge strength and increase cold rolling difficulty, so that the design of low Mn components is adopted, the Mn content is controlled to be 0.9-1.1%, C+Mn/6 is controlled to be less than or equal to 0.36 and less than or equal to 0.4, the strength of the steel plate can be ensured, and good welding performance is realized.
Al: al is conventionally used as a deoxidizer in steel to regulate and control the O content in the steel; in the invention, the effect of Al is important, firstly, al is added to replace part of Si to control the carbide precipitation content and carbide state simultaneously while considering the surface quality; secondly, al promotes pearlite spheroidization in a hot coiling stage, inhibits bainite and martensite transformation possibly caused by high hardenability, ensures lower hot rolling reduction and better downshifting to a cold rolling stage; furthermore, the addition of Al effectively regulates and controls the austenite interval, and ensures the strong plastic matching performance of the steel plate.
Cr: cr element is a conventional additive element, and has the effects of solid solution strengthening and hardenability improvement similar to Mn; the role of Cr in the present invention is critical in that hot rolled edge cracking is improved in place of Mn addition.
Mo: mo element is a conventional additive element, and has the effects of solid solution strengthening and improving hardenability similar to Mn; the role of Mo in the present invention is critical in that it improves hot rolled edge cracking while enhancing hot rolled surface quality instead of Mn addition.
B: b is an essential element of the invention, and the main function of B is to improve the hardenability of the steel plate and prevent the formation of epitaxial hot element bodies in slow cooling and quick cooling stages.
Ti: the conventional addition of Ti can capture free N atoms in steel and play a role of fixing N. Meanwhile, tiN can be separated out in the solidification process, so that the effect of pinning a grain boundary is achieved, and the separation out in the Ti (C, N) hot rolling stage plays the effect of pinning a prior austenite grain boundary and refining the prior austenite grain. In the invention, the action of Ti is more important to exist in a precipitation form among tempered martensite, capture H atoms and resist hydrogen induced cracking.
P: the P element is a harmful element in steel, and the lower the content is, the better. In the invention, the content of the P element is controlled to be less than or equal to 0.015 percent in consideration of cost.
S: the S element is a harmful element in steel, and the lower the content is, the better. In view of cost, the content of S element is controlled to be less than or equal to 0.003 percent.
The second technical scheme of the invention is to provide a preparation method of 1200MPa battery pack steel for new energy automobiles, which comprises smelting, continuous casting, hot rolling, acid washing, cold rolling, continuous deplating and finishing;
Continuous casting:
the alloy components in the range are obtained by smelting in a converter, the ladle temperature is 1530-1560 ℃, the drawing speed of a casting blank is 0.6-0.8 m/min, and the drawing speed is controlled to prevent steel leakage alarm caused by the too high drawing speed.
And (3) hot rolling:
the heating temperature is 1260-1310 ℃, the isothermal temperature is 120-160 min, the Ti atom precipitation behavior is ensured, the good N fixing effect is achieved on the steel plate, the Ti (C, N) precipitation is ensured, the prior austenite grain boundary is pinned, and the prior austenite grain is refined; the control time range is to prevent the TiN from being precipitated and coarsened on the basis of ensuring the sufficient solid solution of the elements, thereby causing the embrittlement of grain boundaries. The initial rolling temperature is 1080-1130 ℃, the final rolling temperature is 900-950 ℃ or above, and the initial rolling temperature ensures the recrystallization behavior of austenite; the finishing temperature prevents the formation of proeutectoid ferrite. Then carrying out ultra-fast cooling and laminar cooling, wherein the ultra-fast cooling speed is 5-8 ℃/s, the laminar cooling speed is 2-3 ℃/s, and the ultra-fast cooling prevents the super-cooled austenite from being quickly transited to a low temperature zone and prevents excessive element distribution; laminar cooling separates out certain proeutectoid ferrite to promote pearlite spheroidization. The coiling temperature is 450-490 ℃, the oxidation and the formation of a grain boundary oxidation layer in the stage are restrained, and the surface quality of the steel plate is ensured.
Acid washing:
And removing the oxide scales generated on the hot rolling surface, wherein the pickling speed is 90-110 m/min. The production cost is improved by preventing too slow acid washing, and the surface quality of the cold-rolled steel plate is ensured by preventing too fast speed.
Cold rolling:
The cold rolling reduction is 40% -58%, so that the rolling reduction of more than 40% of cold rolling is ensured, and tissue fibrosis in cold rolling configuration is promoted; meanwhile, the cold rolling reduction is prevented from being too high, so that deformation resistance is too high, and the rolling is difficult to achieve the target thickness.
Continuous annealing galvanization:
① The heating temperature is 920-950 ℃, the isothermal time is 10-40 s, the austenitizing temperature is ensured by the isothermal temperature, and the ferrite content in the critical zone is controlled to be 8% -12%; the isothermal time is strictly controlled to prevent austenite grains in critical areas from growing, and the completion of austenite phase transformation nucleation and equiaxial treatment are ensured.
② The slow cooling temperature is 720-780 ℃, and the slow cooling speed is controlled to be 1-3 ℃/s; the content of the epitaxial ferrite is controlled to be 10-15 percent.
③ The cooling speed is higher than 45 ℃/s to below 500 ℃, and the pre-cooling effect is achieved to prevent the shape difference caused by the subsequent larger supercooling degree.
④ Directly quenching in water at 80-95 ℃, and then removing surface iron oxide scale through acid washing.
⑤ Reheating: heating to 450-470 deg.c at 10-20 deg.c/s, maintaining the isothermal time for 10-18 s, and controlling the carbide type and the deposition content.
⑥ Alloying hot galvanizing: the steel strip is galvanized by a zinc pot and enters an alloying furnace for isothermal; the alloying temperature is 480-490 ℃, the isothermal temperature is 20-30 s, the temperature is strictly controlled to prevent the insufficient Fe content in the plating layer caused by the too low temperature, the delta phase is ensured to be the main phase in the Zn-Fe layer, and the carbide is prevented from being increased and coarsened caused by the too high temperature. The invention has the beneficial effects that:
(1) The whole flow of the steel plate of the invention considers component control, and the multi-dimension effectively controls the production cost, such as components, processes and the like.
(2) The invention adopts the idea of coupling components and processes to bring forward the process design of quenching water inlet and then temperature rising, ensures the excellent performance of the steel plate, ensures the tensile strength to be more than 1200MPa, the yield strength to be 900-1050 MPa, the elongation to be more than or equal to 12 percent, the hole expansion rate to be more than or equal to 55 percent, the isothermal 5min yield attenuation at 400 ℃ to be less than 200MPa, and the isothermal 5min yield attenuation at 800 ℃ to be less than 500MPa.
(3) The steel for the battery pack fully considers the problem of steel plate strength attenuation by combining the design while finishing static and dynamic performances, and achieves the first aim of protecting safety of the steel for the battery pack.
Detailed Description
The invention is further illustrated by the following examples.
According to the component proportions of the technical scheme, smelting, continuous casting, hot rolling, pickling, cold rolling, continuous annealing, galvanization and finishing are carried out; the method is characterized in that:
And (3) hot rolling:
Heating temperature is 1260-1310 ℃, and isothermal temperature is 120-160 min; the initial rolling temperature is 1080-1130 ℃, the final rolling temperature is 900-950 ℃, then ultra-fast cooling and laminar cooling are carried out, the ultra-fast cooling speed is 5-8 ℃/s, the laminar cooling speed is 2-3 ℃/s, and the coiling temperature is 450-490 ℃;
Acid washing:
The pickling speed is 90-110 m/min;
Cold rolling:
The cold rolling reduction is 40-58%;
Continuous annealing galvanization:
① The isothermal temperature is 920-950 ℃ and the isothermal time is 10-40 s,
② The slow cooling temperature is 720-780 ℃, the slow cooling speed is controlled to be 1-3 ℃/s,
③ Rapidly cooling to below 500 ℃ at a cooling rate of more than 45 ℃/s,
④ Directly enters water with the temperature of 80-95 ℃ for quenching,
⑤ Reheating: heating to 450-470 deg.c at the heating rate of 10-20 deg.c/s for 10-18 s,
⑥ Alloying hot galvanizing: the steel strip is galvanized by a zinc pot and enters an alloying furnace for isothermal treatment, the alloying temperature is 480-490 ℃, and the isothermal treatment lasts for 20-30 s.
Further; during the continuous casting process, the tundish temperature is 1530-1560 ℃ and the casting blank drawing speed is 0.6-0.8 m/min.
The composition of the steel of the example of the invention is shown in Table 1. The main technological parameters of continuous casting and hot rolling of the steel of the embodiment of the invention are shown in Table 2. The main process parameters of the annealing of the steel of the embodiment of the invention are shown in Table 3. The properties of the inventive example steels are shown in Table 4. The microstructure (vol.%) of the steels of the examples of the invention is shown in Table 5.
TABLE 1 composition (wt%) of the inventive example steel
TABLE 2 main process parameters for continuous casting and hot rolling of the inventive example steel
TABLE 3 major heat treatment process parameters for annealing of example steels according to the invention
TABLE 4 Properties of the inventive example Steel
Table 5 microstructure (vol.%) of the inventive example steel
From the above, the microstructure of the steel for battery pack produced by the invention comprises ferrite, epitaxial ferrite, tempered martensite, carbide and other small amounts of unidentified phases in critical zone, wherein each microstructure comprises the following components in percentage by volume: 8-12% of ferrite in a critical area, 10-15% of epitaxial ferrite, 70-75% of tempered martensite and 2.2-3.5% of carbide; preferably, the carbide is mainly theta-type carbide, the volume fraction of the theta-type carbide is more than 70% of all the carbides, and the average grain size is 45-80 nm; the tensile strength is more than 1200MPa, the yield strength is 900-1050 MPa, the elongation is more than or equal to 12%, the hole expansion rate is more than or equal to 55%, isothermal 5-min yield attenuation at 400 ℃ is less than 200MPa, isothermal 5-min yield attenuation at 800 ℃ is less than 500MPa.
The present invention has been properly and fully described in the foregoing embodiments by way of example only, and not by way of limitation, and various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the invention, any modification, equivalent substitution, improvement, etc. should be included in the scope of the invention, and the scope of the invention is defined by the claims.
Claims (7)
1. The 1200MPa battery pack steel for the new energy automobile is characterized by comprising the following ：C：0.20%～0.24%,Si：0.20%～0.40%,Al：0.40%~0.60%,Mn：0.9%～1.1%,Cr：0.30%~0.60%,Mo：0.20%~0.40%,B：0.004%~0.006%,P≤0.015%,S≤0.003%,Ti：0.015～0.035%, parts by weight of Fe and unavoidable impurities as the balance.
2. The 1200MPa battery pack steel for a new energy automobile according to claim 1, wherein C+Mn/6 is more than or equal to 0.36 and less than or equal to 0.4.
3. The 1200MPa battery pack steel for new energy vehicles according to claim 1, wherein the battery pack steel microstructure comprises critical zone ferrite, epitaxial ferrite, tempered martensite, carbide and other minor unidentified phases, wherein each microstructure comprises, in volume percent: 8% -12% of ferrite in the critical area, 10% -15% of epitaxial ferrite, 70% -75% of tempered martensite and 2.2% -3.5% of carbide.
4. The 1200MPa battery pack steel for a new energy automobile according to claim 3, wherein the carbides are mainly θ -type carbides, the volume fraction of the θ -type carbides is 70% or more of all the carbides, and the average grain size is 45 to 80nm.
5. The 1200MPa battery pack steel for the new energy automobile according to claim 1, wherein the tensile strength of the battery pack steel is more than 1200MPa, the yield strength is 900-1050MPa, the elongation is more than or equal to 12%, the hole expansion rate is more than or equal to 55%, the isothermal 5min yield failure is less than 200MPa at 400 ℃, and the isothermal 5min yield failure is less than 500MPa at 800 ℃.
6. A method for preparing the 1200MPa battery pack steel for the new energy automobile according to any one of claims 1-5, comprising smelting, continuous casting, hot rolling, pickling, cold rolling, continuous annealing, galvanization and finishing; the method is characterized in that:
And (3) hot rolling:
the heating temperature is 1260-1310 ℃, and the isothermal temperature is 120-160 min; the initial rolling temperature is 1080-1130 ℃, the final rolling temperature is 900-950 ℃, then ultra-fast cooling and laminar cooling are carried out, the ultra-fast cooling speed is 5-8 ℃/s, the laminar cooling speed is 2-3 ℃/s, and the coiling temperature is 450-490 ℃;
Acid washing:
The pickling speed is 90-110 m/min;
Cold rolling:
the cold rolling reduction rate is 40% -58%;
Continuous annealing galvanization:
① The isothermal temperature is 920-950 ℃ and the isothermal time is 10-40 s,
② The slow cooling temperature is 720-780 ℃, the slow cooling speed is controlled to be 1-3 ℃/s,
③ Rapidly cooling to below 500 ℃ at a cooling rate of more than 45 ℃/s,
④ Directly quenching in water at 80-95 ℃,
⑤ Reheating: heating to 450-470 ℃ at a heating rate of 10-20 ℃/s, and keeping the isothermal time at 10-18 s,
⑥ Alloying hot galvanizing: the steel strip is galvanized by a zinc pot and enters an alloying furnace for isothermal treatment, the alloying temperature is 480-490 ℃, and the isothermal treatment lasts for 20-30 s.
7. The method for preparing the 1200MPa battery pack steel for the new energy automobile, which is disclosed in claim 6, is characterized in that: in the continuous casting process, the tundish temperature is 1530-1560 ℃, and the casting blank drawing speed is 0.6-0.8 m/min.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310476363.1A CN117187682B (en) | 2023-04-28 | 2023-04-28 | 1200MPa battery pack steel for new energy automobile and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310476363.1A CN117187682B (en) | 2023-04-28 | 2023-04-28 | 1200MPa battery pack steel for new energy automobile and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN117187682A CN117187682A (en) | 2023-12-08 |
| CN117187682B true CN117187682B (en) | 2024-05-14 |
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