WO2024048132A1 - 高強度鋼板およびその製造方法ならびに部材およびその製造方法 - Google Patents

高強度鋼板およびその製造方法ならびに部材およびその製造方法 Download PDF

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WO2024048132A1
WO2024048132A1 PCT/JP2023/027131 JP2023027131W WO2024048132A1 WO 2024048132 A1 WO2024048132 A1 WO 2024048132A1 JP 2023027131 W JP2023027131 W JP 2023027131W WO 2024048132 A1 WO2024048132 A1 WO 2024048132A1
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Prior art keywords
less
steel plate
temperature
hot
strength
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Ceased
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PCT/JP2023/027131
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English (en)
French (fr)
Japanese (ja)
Inventor
霊玲 楊
勇樹 田路
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JFE Steel Corp
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JFE Steel Corp
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Priority to US19/105,851 priority Critical patent/US20260071306A1/en
Priority to EP23859901.3A priority patent/EP4560038A4/en
Priority to CN202380060103.4A priority patent/CN119654435A/zh
Priority to JP2023569663A priority patent/JP7761672B2/ja
Priority to KR1020257006619A priority patent/KR20250044383A/ko
Priority to MX2025002002A priority patent/MX2025002002A/es
Publication of WO2024048132A1 publication Critical patent/WO2024048132A1/ja
Anticipated expiration legal-status Critical
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    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
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    • C21D8/00—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment
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    • C21D8/00—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
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    • C21D8/00—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0236—Cold rolling
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    • C21D8/00—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0247—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
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    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
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    • C23C2/06—Zinc or cadmium or alloys based thereon
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/14—Removing excess of molten coatings; Controlling or regulating the coating thickness
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    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/008—Martensite

Definitions

  • the present invention relates to a high-strength steel plate having a yield strength (YS) of 800 MPa or more, a method for manufacturing the same, and a member and a method for manufacturing the same.
  • Yield strength 800 MPa or more
  • Patent Documents 1 to 3 disclose high-strength steel plates having a yield strength of 800 MPa or more.
  • crash strength In order to form a high-strength steel plate having a yield strength of 800 MPa or more into automobile parts, good workability is required.
  • steel plates used as automobile parts have excellent crash strength (hereinafter referred to as "crash strength") and suppress the propagation of cracks caused by external forces during a collision (excellent crack retention). is also required.
  • an object of the present invention is to provide a high-strength steel plate that has a yield strength of 800 MPa or more and is excellent in workability, impact strength, and crack retention.
  • a steel plate wherein the amount of diffusible hydrogen in the steel of the steel plate is 0.50 mass ppm or less, the steel plate has a component composition and a microstructure, and the component composition is in mass %, C : 0.150 to 0.500%, Si: 0.01 to 3.00%, Mn: 1.50 to 4.00%, P: 0.100% or less, S: 0.0200% or less, Al: 0.100% or less, N: 0.0100% or less, and O: 0.0100% or less, with the remainder consisting of Fe and inevitable impurities, and the above microstructure has a total area of tempered martensite and bainite.
  • the above component composition further includes, in mass %, B: 0.0100% or less, Ti: 0.200% or less, Nb: 0.200% or less, V: 0.200% or less, W: 0.
  • the plating layer is a hot-dip galvanized layer, an alloyed hot-dip galvanized layer, or an electrogalvanized layer.
  • a method for producing the high-strength steel plate described in [1] above comprising hot rolling a steel slab having the composition described in [1] above to obtain a hot-rolled steel plate; A hot rolled steel plate is subjected to cold rolling to obtain a cold rolled steel plate, and the cold rolled steel plate is heated for 10 to 500 seconds at a heating temperature T1 of 750 to 950°C, and a cooling stop temperature T2 of 120°C or more and less than 280°C. and then reheated to a reheating temperature T3, recooled without holding at the reheating temperature T3, and held at a temperature T4 lower than the reheating temperature T3 for 1 s or more, and expressed by the following formula (1).
  • the heat input influence index J from the cooling stop temperature T2 to the reheating temperature T3 is 1500 to 4000, and the cold rolled steel sheet held at the temperature T4 has a surface roughness of 1.5 to 5.
  • a method for producing a high-strength steel plate according to [2] above comprising hot rolling a steel slab having the composition described in [2] above to obtain a hot-rolled steel plate; A hot rolled steel plate is subjected to cold rolling to obtain a cold rolled steel plate, and the cold rolled steel plate is heated for 10 to 500 seconds at a heating temperature T1 of 750 to 950°C, and a cooling stop temperature T2 of 120°C or more and less than 280°C. and then reheated to a reheating temperature T3, recooled without holding at the reheating temperature T3, and held at a temperature T4 lower than the reheating temperature T3 for 1 s or more, and expressed by the following formula (1).
  • the heat input influence index J from the cooling stop temperature T2 to the reheating temperature T3 is 1500 to 4000, and the cold rolled steel sheet held at the temperature T4 has a surface roughness of 1.5 to 5.
  • a high-strength steel plate that has a yield strength of 800 MPa or more and is excellent in workability, crash strength, and crack retention.
  • FIG. 3 is a schematic diagram showing a hat member subjected to a three-point bending test.
  • the high-strength steel plate of this embodiment includes a steel plate, and may further include a plating layer on the surface of this steel plate, as described later.
  • the steel plate included in the present high-strength steel plate has the composition and microstructure described below, and satisfies the amount of diffusible hydrogen in steel described below.
  • High strength means that the yield strength (YS) is 800 MPa or more.
  • This high-strength steel plate has a yield strength of 800 MPa or more, and is excellent in workability, crash strength, and crack retention. Therefore, since the material has sufficient strength against collisions, it is suitably used as a part of a transportation machine such as an automobile, for example.
  • general processing methods such as press processing can be used without restriction.
  • general welding methods such as spot welding and arc welding can be used without limitation.
  • the thickness of the steel plate is not particularly limited, and is, for example, 0.5 mm or more and 3.0 mm or less.
  • Component composition The component composition of the steel plate included in the present high-strength steel plate (hereinafter also referred to as “main component composition” for convenience) will be explained. “%” in this component composition means “% by mass” unless otherwise specified.
  • C (C: 0.150-0.500%) C generates martensite and increases the strength of the steel plate. If the amount of C is too small, the total area ratio of tempered martensite and bainite will decrease, resulting in a decrease in impact strength and yield strength. Therefore, the amount of C is 0.150% or more, preferably 0.180% or more, and more preferably 0.200% or more. On the other hand, if the amount of C is too large, the structure A having a nanohardness of 7 GPa or more, which becomes the starting point of cracks, will increase, resulting in a decrease in workability. Therefore, the amount of C is 0.500% or less, preferably 0.460% or less, and more preferably 0.400% or less.
  • Si suppresses the formation of carbides during heat treatment and affects the hardness of the structure and the concentration of solid solution carbon in retained austenite.
  • the amount of Si is 0.01% or more, and 0.50% or more. It is preferably 0.80% or more, and more preferably 0.80% or more.
  • the amount of Si is 3.00% or less, preferably 2.60% or less, and more preferably 2.40% or less.
  • Mn affects the area ratio of tempered martensite and bainite. From the viewpoint of obtaining good impact strength and yield strength of 800 MPa or more, the Mn content is 1.50% or more, preferably 1.90% or more, and more preferably 2.30% or more. On the other hand, if the amount of Mn is too large, the structure A having a nanohardness of 7 GPa or more, which becomes the starting point of cracks, increases, resulting in a decrease in workability. Therefore, the Mn amount is 4.00% or less, preferably 3.50% or less, and more preferably 3.30% or less.
  • the amount of P is 0.100% or less, preferably 0.030% or less, and more preferably 0.010% or less.
  • the lower limit of the amount of P is not particularly limited, but since P is a solid solution strengthening element and increases the strength of the steel plate, it is preferably 0.001%, more preferably 0.002%, and even more preferably 0.003%. preferable.
  • the amount of S is 0.0200% or less, preferably 0.0100% or less, and more preferably 0.0020% or less.
  • the lower limit of the amount of S is not particularly limited, but due to production technology constraints, it is preferably 0.0001%, more preferably 0.0002%, and even more preferably 0.0003%.
  • Al increases the A3 transformation point. As a result, ferrite increases and the area ratio of tempered martensite and bainite decreases. Therefore, the amount of Al is 0.100% or less, preferably 0.080% or less, and more preferably 0.060% or less.
  • the lower limit of the amount of Al is not particularly limited, but is, for example, 0.010%, preferably 0.020%, since it suppresses the formation of carbides during heat treatment and promotes the formation of retained austenite.
  • N (N: 0.0100% or less) N combines with Ti to form TiN, which becomes a starting point for cracks, resulting in reduced workability. Therefore, the amount of N is 0.0100% or less, preferably 0.0080% or less, and more preferably 0.0060% or less.
  • the lower limit of the amount of N is not particularly limited, but due to constraints on production technology, it is preferably 0.0001%, more preferably 0.0003%, and even more preferably 0.0005%.
  • O forms oxides, which serve as starting points for cracks, resulting in reduced workability. Therefore, the amount of O is 0.0100% or less, preferably 0.0050% or less, and more preferably 0.0020% or less.
  • This component composition may further contain, in mass %, at least one element selected from the group consisting of the elements described below.
  • ((B: 0.0100% or less)) B is an element that can improve the hardenability of a steel sheet by segregating at austenite grain boundaries, and increases the yield strength of the steel sheet, so it is preferably added.
  • the amount of B is preferably 0.0100% or less, more preferably 0.0050% or less, even more preferably 0.0040% or less, and particularly preferably 0.0030% or less.
  • the lower limit of the amount of B is not particularly limited, but from the viewpoint of obtaining the effect of adding B, it is, for example, 0.0005%, preferably 0.0010%.
  • Ti ((Ti: 0.200% or less)) Ti is preferably added because it increases the yield strength of the steel sheet by forming fine carbides, nitrides, or carbonitrides during hot rolling or heat treatment.
  • the amount of Ti is preferably 0.200% or less, more preferably 0.100% or less, and even more preferably 0.050% or less.
  • the lower limit of the amount of Ti is not particularly limited, but from the viewpoint of obtaining the effect of adding Ti, it is, for example, 0.005%, and preferably 0.010%.
  • Nb, V, and W increase the yield strength of the steel sheet by forming fine carbides, nitrides, or carbonitrides during hot rolling or heat treatment, so it is preferable to add them.
  • the Nb amount is preferably 0.200% or less, more preferably 0.100% or less, and even more preferably 0.050% or less.
  • the lower limit is not particularly limited, but from the viewpoint of obtaining the effect of adding Nb, it is, for example, 0.005%, preferably 0.010%.
  • the amount of V is preferably 0.200% or less, more preferably 0.100% or less, and even more preferably 0.050% or less.
  • the lower limit is not particularly limited, but from the viewpoint of obtaining the effect of adding V, it is, for example, 0.005%, preferably 0.010%.
  • the amount of W is preferably 0.100% or less, more preferably 0.080% or less, and even more preferably 0.050% or less.
  • the lower limit is not particularly limited, but from the viewpoint of obtaining the effect of adding W, it is, for example, 0.010%, preferably 0.020%.
  • Mo and Cr are preferably added because they increase the yield strength of the steel plate by improving the hardenability of the steel plate.
  • the amount of Mo is preferably 1.000% or less, more preferably 0.800% or less, and even more preferably 0.500% or less.
  • the lower limit is not particularly limited, but from the viewpoint of obtaining the effect of adding Mo, it is, for example, 0.010%, preferably 0.020%.
  • the amount of Cr is preferably 1.000% or less, more preferably 0.800% or less, and even more preferably 0.500% or less.
  • the lower limit is not particularly limited, but from the viewpoint of obtaining the effect of adding Cr, it is, for example, 0.010%, preferably 0.020%.
  • Sb and Sn increase the yield strength of the steel plate by suppressing decarburization on the surface of the steel plate, so it is preferable to add Sb and Sn.
  • the amount of Sb is preferably 0.200% or less, more preferably 0.080% or less, and even more preferably 0.040% or less.
  • the lower limit is not particularly limited, but from the viewpoint of obtaining the effect of adding Sb, it is, for example, 0.001%, preferably 0.002%.
  • the amount of Sn is preferably 0.200% or less, more preferably 0.080% or less, and even more preferably 0.040% or less.
  • the lower limit is not particularly limited, but from the viewpoint of obtaining the effect of adding Sn, it is, for example, 0.001%, preferably 0.002%.
  • Zr and Te are preferably added because they make the shape of nitrides and sulfides spheroidal and improve workability.
  • the Zr amount is preferably 0.1000% or less, more preferably 0.0800% or less, and even more preferably 0.0500% or less.
  • the lower limit is not particularly limited, but from the viewpoint of obtaining the effect of adding Zr, it is, for example, 0.0050%, preferably 0.0100%.
  • the amount of Te is preferably 0.100% or less, more preferably 0.080% or less, and even more preferably 0.050% or less.
  • the lower limit is not particularly limited, but from the viewpoint of obtaining the effect of adding Te, it is, for example, 0.005%, preferably 0.010%.
  • the amount of Cu is preferably 1.000% or less, more preferably 0.800% or less, and even more preferably 0.500% or less.
  • the lower limit is not particularly limited, but from the viewpoint of obtaining the effect of adding Cu, it is, for example, 0.010%, preferably 0.020%.
  • Ni ((Ni: 1.000% or less)) Since Ni increases the yield strength of the steel plate by improving the hardenability of the steel plate, it is preferable to add Ni. However, when the amount of Ni is excessively large, hard martensite increases, resulting in deterioration of workability. Therefore, the Ni amount is preferably 1.000% or less, more preferably 0.800% or less, and even more preferably 0.500% or less.
  • the lower limit is not particularly limited, but from the viewpoint of obtaining the effect of adding Ni, it is, for example, 0.010%, preferably 0.020%.
  • Ca, Mg, and REM (Rare Earth Metal) are preferably added because they spheroidize the shape of precipitates such as sulfides and oxides and improve workability.
  • the amount of Ca is preferably 0.0100% or less, more preferably 0.0050% or less, and even more preferably 0.0040% or less.
  • the lower limit is not particularly limited, but from the viewpoint of obtaining the effect of adding Ca, it is, for example, 0.0005%, preferably 0.0010%.
  • the amount of Mg is preferably 0.0100% or less, more preferably 0.0050% or less, and even more preferably 0.0040% or less.
  • the lower limit is not particularly limited, but from the viewpoint of obtaining the effect of Mg addition, it is, for example, 0.0005%, preferably 0.0010%.
  • the amount of REM is preferably 0.0100% or less, more preferably 0.0040% or less, and even more preferably 0.0030% or less.
  • the lower limit is not particularly limited, but from the viewpoint of obtaining the effect of adding REM, it is, for example, 0.0005%, preferably 0.0010%.
  • Co ((Co: 0.010% or less, Ta: 0.10% or less, Hf: 0.10% or less, Bi: 0.200% or less))
  • Co, Ta, Hf, and Bi make the shape of the precipitates spherical and improve workability, so it is preferable to add them.
  • the Co amount is preferably 0.010% or less, more preferably 0.008% or less, and even more preferably 0.007% or less.
  • the lower limit is not particularly limited, but from the viewpoint of obtaining the effect of adding Co, it is, for example, 0.001%, preferably 0.002%.
  • the amount of Ta is preferably 0.10% or less, more preferably 0.08% or less, and even more preferably 0.07% or less.
  • the lower limit is not particularly limited, but from the viewpoint of obtaining the effect of adding Ta, it is, for example, 0.01%, preferably 0.02%.
  • the amount of Hf is preferably 0.10% or less, more preferably 0.08% or less, and even more preferably 0.07% or less.
  • the lower limit is not particularly limited, but from the viewpoint of obtaining the effect of adding Hf, it is, for example, 0.01%, preferably 0.02%.
  • the amount of Bi is preferably 0.200% or less, more preferably 0.100% or less, and even more preferably 0.080% or less.
  • the lower limit is not particularly limited, but from the viewpoint of obtaining the effect of adding REM, it is, for example, 0.001%, preferably 0.005%.
  • the remainder in this component composition consists of Fe and unavoidable impurities.
  • the microstructure of the steel plate included in the present high-strength steel sheet (hereinafter also referred to as "the present microstructure" for convenience) will be explained.
  • the area ratio is the area ratio with respect to the entire microstructure. The area ratio of each tissue is determined by the method described in the Examples below.
  • Total area ratio of tempered martensite and bainite 55-95%) From the viewpoint of stably ensuring good impact strength and yield strength, the total area ratio of tempered martensite and bainite is 55% or more, preferably 58% or more, and more preferably 60% or more.
  • this total area ratio is 95% or less, preferably 92% or less, and more preferably 88% or less.
  • the structure A having a nanohardness of 7 GPa or more is fine and hard, and improves crack retention by stopping the propagation of cracks generated by external force at the time of collision.
  • the structure B having a nanohardness of 6 GPa or less has high toughness and thus improves workability.
  • the abundance ratio (A/B) of structure A and structure B both crack arrestability and workability are excellent. Since the crack retention property is excellent, the abundance ratio (A/B) is 0.8 or more, preferably 1.0 or more, and more preferably 1.1 or more.
  • the abundance ratio (A/B) between the structure A and the structure B is 2.5 or less, preferably 2.3 or less, and more preferably 2.0 or less.
  • Nanohardness is hardness measured using a nanoindentation method, and specifically, it is determined by the method described in the Examples below. Hardness other than nano-hardness (for example, Vickers hardness) cannot evaluate the plastic deformation resistance in a local region at the submicron level of the tissue.
  • Solid carbon concentration in retained austenite 0.50 to 0.90% by mass
  • This microstructure includes retained austenite.
  • the concentration of solute carbon in retained austenite increases, the hardness of martensite that transforms from retained austenite increases significantly when stress is repeatedly applied, which increases the number of crack initiation points and deteriorates workability. Therefore, the solid solution carbon concentration in the retained austenite is 0.90% by mass or less, preferably 0.85% by mass or less, and more preferably 0.80% by mass.
  • the solid solution carbon concentration in the retained austenite is 0.50% by mass or more, preferably 0.60% by mass or more, and more preferably 0.70% by mass or more.
  • the microstructure may include a structure other than tempered martensite, bainite, and retained austenite (residual structure).
  • the residual structure include known structures such as fresh martensite; pearlite; ferrite; iron-based carbonitride; alloy carbonitride; inclusions such as MnS and Al 2 O 3 ;
  • the area ratio of the remaining tissue is preferably 20% or less, more preferably 10% or less, and even more preferably 5% or less. As long as the area ratio of the remaining tissue is within this range, the effects of the present invention are not impaired.
  • ⁇ Amount of diffusible hydrogen in steel 0.50 mass ppm or less ⁇ If the amount of diffusible hydrogen in the steel is too high, delayed fracture will occur and workability will deteriorate. Therefore, the amount of diffusible hydrogen in steel is 0.50 mass ppm or less, preferably 0.30 mass ppm or less, and more preferably 0.20 mass ppm or less. The amount of diffusible hydrogen in steel is determined by the method described in Examples below.
  • the present high-strength steel plate may further include a plating layer on the surface of the steel plate from the viewpoint of improving corrosion resistance and the like.
  • the plating layer include a hot-dip galvanized layer, an alloyed hot-dip galvanized layer, and an electrogalvanized layer.
  • the plating layer is formed by a plating process described below.
  • This manufacturing method is also a method for manufacturing the above-mentioned high-strength steel plate.
  • the temperature when heating or cooling a steel slab, steel plate, etc. shown below means the surface temperature of the steel slab, steel plate, etc. unless otherwise specified.
  • the method for producing molten steel to become a steel slab (steel material) is not particularly limited, and any known method using a converter, electric furnace, etc. can be adopted.
  • a steel slab is obtained from molten steel by a continuous casting method. Steel slabs may be obtained using other methods such as ingot-blowing rolling and thin slab continuous casting.
  • ⁇ Hot rolling> In this manufacturing method, first, a steel slab having the above-mentioned main component composition is hot rolled. Thereby, a hot rolled steel plate is obtained.
  • the steel slab When hot rolling, the steel slab may be reheated in a heating furnace and then rolled. If the steel slab maintains a temperature equal to or higher than a predetermined temperature, the steel slab may be directly rolled without being heated.
  • hot rolling a steel slab is subjected to rough rolling and finish rolling. It is preferable to heat the steel slab to dissolve carbides in the steel slab before rough rolling.
  • the temperature at which the steel slab is heated is preferably 1100°C or higher, more preferably 1150°C or higher.
  • the steel slab heating temperature is preferably 1300°C or lower, more preferably 1280°C or lower.
  • the finish rolling temperature is preferably 700 to 1100°C, more preferably 800 to 1000°C.
  • the rolling ratio of cold rolling is preferably 30% or more, more preferably 35% or more.
  • the upper limit is not particularly limited, and is, for example, 70% or less, preferably 65% or less.
  • FIG. 1 is a chart showing an example of heat treatment.
  • a cold rolled steel plate is generally heated at a heating temperature T1, then cooled to a cooling stop temperature T2, and then reheated to a reheating temperature T3 without being held at the reheating temperature T3.
  • Recool In recooling, the cold rolled steel sheet is held at a temperature T4 that is lower than the reheating temperature T3.
  • a cold-rolled steel sheet that has been heat treated and further subjected to temper rolling corresponds to the steel sheet included in the present high-strength steel sheet described above.
  • Heating temperature T1 750-950°C
  • heating time t1 10-500s ⁇
  • a cold rolled steel plate is heated at a heating temperature T1.
  • the heating temperature T1 is 750°C or higher, preferably 800°C or higher, and more preferably 850°C or higher.
  • the heating time t1 is 10 seconds or more, preferably 50 seconds or more, and more preferably 80 seconds or more.
  • the heating temperature T1 is 950°C or lower, preferably 930°C or lower, and more preferably 900°C or lower.
  • the heating time t1 is 500 seconds or less, preferably 300 seconds or less, and more preferably 200 seconds or less.
  • ⁇ Cooling stop temperature T2 120°C or higher and lower than 280°C ⁇
  • the cold rolled steel sheet heated at the heating temperature T1 is cooled to a cooling stop temperature T2. If the cooling stop temperature T2 is too low, the total area ratio of tempered martensite and bainite will become high, and the abundance ratio (A/B) will become too large, resulting in poor workability. Therefore, the cooling stop temperature T2 is 120°C or higher, preferably 140°C or higher, and more preferably 150°C or higher.
  • the cooling stop temperature T2 is less than 280°C, preferably 270°C or less, and more preferably 260°C or less.
  • the reheating temperature T3 is not particularly limited as long as it satisfies the heat input influence index J described below.
  • the reheating temperature T3 is, for example, 280°C or higher, preferably 290°C or higher, and more preferably 300°C or higher.
  • the reheating temperature T3 is, for example, 400°C or lower, preferably 380°C or lower, and more preferably 350°C or lower.
  • the nanohardness of each structure constituting the microstructure changes depending on the state of carbon in each structure.
  • the heat input influence index J affects not only the state of carbon existence but also the diffusion rate and location of carbon. If the heat input influence index J is too low, carbon in the structure exists as a solid solution, so the number of structures A with nanohardness of 7 GPa or more increases, and the abundance ratio (A/B) becomes too large, resulting in poor workability. deteriorates. Furthermore, the concentration of solid solute carbon in the retained austenite becomes too high, resulting in poor workability. Therefore, the heat input influence index J is 1500 or more, preferably 1800 or more, and more preferably 2000 or more.
  • the heat input influence index J is 4000 or less, preferably 3800 or less, and more preferably 3500 or less.
  • the lower limit of the temperature T4 is not particularly limited, but is, for example, 180°C, preferably 200°C, and more preferably 220°C.
  • the holding time t4 is 1 s or more, preferably 3 s or more, and more preferably 5 s or more.
  • ⁇ Surface roughness of roll 1.5-5.0 ⁇ m ⁇
  • the surface roughness of the roll the mobile dislocations introduced in local regions at the submicron level are adjusted, and the hardness distribution of the structure is controlled. If the surface roughness of the roll is too small, the abundance ratio (A/B) will become too small and crack retention will deteriorate. Therefore, the surface roughness of the roll is 1.5 ⁇ m or more, preferably 1.8 ⁇ m or more, and more preferably 2.0 ⁇ m or more.
  • the surface roughness of the roll is 5.0 ⁇ m or less, preferably 4.5 ⁇ m or less, and more preferably 4.0 ⁇ m or less.
  • the surface roughness of the roll is the arithmetic mean roughness Ra measured in accordance with JIS B 0601.
  • a plating layer may be formed on the surface of a cold-rolled steel sheet that has been subjected to temper rolling by performing plating treatment.
  • the plating layer include a hot-dip galvanized layer, an alloyed hot-dip galvanized layer, and an electrogalvanized layer.
  • the plating treatment is preferably hot-dip galvanizing, alloyed hot-dip galvanizing, or electrogalvanizing.
  • a steel plate is immersed in a zinc bath at a bath temperature of 440 to 500° C. to perform hot-dip galvanizing. After that, it is preferable to adjust the adhesion amount of the plating layer by gas wiping or the like.
  • a zinc bath having a component composition in which the Al content is 0.10 to 0.23% by mass, and the balance is Zn and unavoidable impurities is preferable.
  • the alloying temperature is preferably 450 to 600°C, more preferably 470 to 550°C, even more preferably 470 to 530°C.
  • An electrogalvanized layer is formed by electrogalvanizing.
  • the electrogalvanized layer is not particularly limited, and conventionally known electrogalvanized layers are suitably used.
  • the electrogalvanized layer may be a zinc alloy plated layer in which an appropriate amount of an element such as Fe, Cr, Ni, Mn, Co, Sn, Pb, or Mo is added to Zn depending on the purpose.
  • the coating weight of the galvanized steel sheet (GI), alloyed galvanized steel sheet (GA), and electrogalvanized steel sheet (EG) is preferably 20 to 80 g/m 2 per side (double-sided plating).
  • the plated steel plate is cooled to a temperature of, for example, 50° C. or lower.
  • a steel plate cooled to a temperature of 50° C. or lower may be rolled at an elongation rate of 0.05 to 1.00%.
  • the elongation rate is preferably 0.08 to 0.70%.
  • This rolling may be carried out on an apparatus that is continuous with the apparatus (plating apparatus) for carrying out the galvanizing process, or may be carried out on an apparatus that is discontinuous with the plating apparatus.
  • the target elongation rate may be achieved by one rolling, or the target elongation rate may be achieved by rolling a plurality of times. Note that the rolling described here generally refers to temper rolling, but rolling by processing using a leveler or the like may be used as long as an elongation rate equivalent to that of temper rolling can be imparted.
  • the holding temperatures such as heating temperature and reheating temperature do not need to be constant as long as they are within the above-mentioned temperature range.
  • the cooling rate may be changed during cooling as long as it is within the above-mentioned rate range.
  • the heat treatment may be performed in any equipment as long as the conditions such as the temperature range described above are satisfied.
  • This member is a member that uses the above-mentioned high-strength steel plate at least in part, and is, for example, formed by processing (such as press working) the high-strength steel plate into a desired shape.
  • This member is preferably a member for automobile parts.
  • the member for automobile parts may include a steel plate other than the present high-strength steel plate as a material.
  • this high-strength steel plate has a yield strength of 800 MPa or more, and is excellent in workability, crash strength, and crack retention. For this reason, this material has excellent workability, crash strength, and crack arrestability, and can contribute to reducing the weight of the vehicle body, so it is particularly used for automobile frame structural parts or automobile reinforcement parts among automobile parts. It is suitable as a general member.
  • the present member is obtained, for example, by subjecting the present high-strength steel plate to at least one of forming and bonding.
  • the molding process is not particularly limited, and examples thereof include press working.
  • the joining process is not particularly limited, and includes, for example, general welding such as spot welding and arc welding; caulking using rivets, etc.
  • plating treatment is applied to both sides of cold rolled steel sheet (CR) after temper rolling, such as hot dip galvanized steel sheet (GI), galvannealed steel sheet (GA) or electrogalvanized steel sheet ( EG) was obtained.
  • GI hot dip galvanized steel sheet
  • GA galvannealed steel sheet
  • EG electrogalvanized steel sheet
  • a hot-dip galvanizing bath when manufacturing GI, a zinc bath containing Al: 0.20% by mass, with the balance consisting of Zn and inevitable impurities is used, and when manufacturing GA, Al: 0.20% by mass is used.
  • a zinc bath was used containing 14% by weight, with the remainder consisting of Zn and unavoidable impurities.
  • the bath temperature was 470° C. in both GI and GA production.
  • the amount of plating layer deposited was 45 to 72 g/m 2 per side when manufacturing GI, and 45 g/m 2 per side when manufacturing GA.
  • the alloying temperature was 500°C.
  • the composition of the GI plating layer was such that it contained Fe: 0.1 to 1.0% by mass, Al: 0.2 to 1.0% by mass, and the remainder consisted of Fe and inevitable impurities.
  • the composition of the GA plating layer was such that it contained Fe: 7 to 15% by mass, Al: 0.1 to 1.0% by mass, and the remainder consisted of Fe and inevitable impurities.
  • electrogalvanizing was performed using an electrogalvanizing line so that the amount of plating layer deposited was 30 g/m 2 per side.
  • heat-treated cold rolled steel sheets CR
  • hot-dip galvanized steel sheets GI
  • alloyed hot-dip galvanized steel sheets G
  • electrogalvanized steel sheets EG
  • the obtained steel plate was polished so that the cross section (L cross section) parallel to the rolling direction at 1/4 of the plate thickness was the observation surface.
  • the observation surface was corroded using 1% by volume nital, and then observed using a scanning electron microscope (SEM) at a magnification of 3000 times.
  • SEM scanning electron microscope
  • the observation surface was observed for 10 fields, and a SEM image was obtained.
  • the obtained SEM image was analyzed to determine the total area ratio (unit: %) of tempered martensite and bainite. More specifically, the dark gray portions in the obtained SEM image were determined to be tempered martensite and bainite, and the area ratio (average area ratio of 10 fields of view) was determined.
  • Image-Pro manufactured by Media Cybernetics was used as analysis software.
  • the obtained steel plate was polished so that the cross section (L cross section) parallel to the rolling direction at 1/4 of the plate thickness was the observation surface.
  • the observation surface was mirror polished using diamond paste, and then finished polished using colloidal silica.
  • the nanohardness of the observed surface was measured at 225 points using a nanoindentation device equipped with a Berkovich indenter.
  • the measurement conditions were a loading speed and an unloading speed of 50 ⁇ N/s, a maximum load of 500 ⁇ N, a data collection pitch of 5 ms, and a distance between indentations of 2 ⁇ m or more.
  • the measurement points with nanohardness of 7 GPa or more are tissue A
  • the measurement points with nanohardness 6 of GPa or less are tissue B
  • the ratio of the number of measurement points is defined as tissue A and tissue B. It was determined as the abundance ratio (A/B).
  • the content of carbon (C) in the retained austenite (unit: mass %) is determined, and this is calculated as the solid solution in the retained austenite. It was taken as carbon concentration.
  • a is the lattice constant of retained austenite (unit: ⁇ )
  • ⁇ is the value obtained by dividing the diffraction peak angle of the (220) plane by 2 (unit: rad).
  • a is the lattice constant of the retained austenite (unit: ⁇ )
  • [M] is the content of element M in the retained austenite (unit: mass %).
  • the content of elements M other than C the content of each element in the composition of the entire steel sheet (specifically, for example, the main composition described above) is used.
  • the amount of diffusible hydrogen in the steel is preferably 0.50 mass ppm or less.
  • ⁇ Tensile test ⁇ A No. 5 test piece as described in JIS Z 2241, whose longitudinal direction (tensile direction) is 90° with respect to the rolling direction, was taken from the obtained steel plate.
  • a tensile test based on JIS Z 2241 was performed five times using the sampled test piece, and the yield strength (YS) and elongation (El) were determined from the average values of the five tests. If YS is 800 MPa or more, it can be evaluated as having high strength. If El is 8.0% or more, it can be evaluated that ductility is good and workability is excellent.
  • FIG. 2A is a sectional view showing the hat member 1.
  • FIG. 2A the dimensions of the hat member 1 are shown.
  • the hat member 1 is joined to the flat plate 2 by spot welding (nugget diameter: 4.5 ⁇ t, pitch between spots: 35 mm).
  • the flat plate 2 is a cold-rolled steel plate without a plating layer, has a tensile strength (TS) of 590 MPa, and a plate thickness t that is the same as that of the hat member 1 (1.2 mm).
  • TS tensile strength
  • FIG. 2B is a schematic diagram showing the hat member 1 subjected to a three-point bending test. Various dimensions are also shown in FIG. 2B.
  • a flat plate 2 joined to a hat member 1 is supported by a support member 3 which is a rigid body.
  • the impactor 4 which is a rigid body, is moved from above toward the hat member 1 at a speed of 1 m/s. In this way, a three-point bending test is performed.
  • a three-point bending test was performed three times for each steel plate, and the average value of the maximum loads determined each time was taken as the maximum load for that steel plate.
  • the maximum load was 40 kN or more, " ⁇ ” was written, when it was 30 kN or more and less than 40 kN, " ⁇ ” was written, and when it was less than 30 kN, "x” was written in Table 3 below. If the rating is " ⁇ ” or " ⁇ ”, it can be evaluated that the collision strength is excellent.
  • Test method Roll support, punch pushing Roll diameter: ⁇ 30mm Punch tip R: 0.4mm Distance between rolls: (plate thickness x 2) + 0.5mm Stroke speed: 20mm/min Test piece size: 60mm x 60mm Bending direction: rolling right angle method

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PCT/JP2023/027131 2022-08-29 2023-07-25 高強度鋼板およびその製造方法ならびに部材およびその製造方法 Ceased WO2024048132A1 (ja)

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US19/105,851 US20260071306A1 (en) 2022-08-29 2023-07-25 High strength steel sheet, method for producing same, member, and method for producing same
EP23859901.3A EP4560038A4 (en) 2022-08-29 2023-07-25 HIGH-STRENGTH STEEL SHEET, ITS PRODUCTION PROCESS, ELEMENT AND ITS PRODUCTION PROCESS
CN202380060103.4A CN119654435A (zh) 2022-08-29 2023-07-25 高强度钢板及其制造方法以及构件及其制造方法
JP2023569663A JP7761672B2 (ja) 2022-08-29 2023-07-25 高強度鋼板およびその製造方法ならびに部材およびその製造方法
KR1020257006619A KR20250044383A (ko) 2022-08-29 2023-07-25 고강도 강판 및 그의 제조 방법 그리고 부재 및 그의 제조 방법
MX2025002002A MX2025002002A (es) 2022-08-29 2023-07-25 Lamina de acero de alta resistencia metodo para producirla, miembro y metodo para producirlo

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2026063176A1 (ja) * 2024-09-18 2026-03-26 Ｊｆｅスチール株式会社 高強度鋼板およびその製造方法
WO2026063174A1 (ja) * 2024-09-18 2026-03-26 Ｊｆｅスチール株式会社 高強度鋼板およびその製造方法
WO2026070560A1 (ja) * 2024-09-26 2026-04-02 Ｊｆｅスチール株式会社 高強度熱延鋼板、部材、およびそれらの製造方法
WO2026070559A1 (ja) * 2024-09-26 2026-04-02 Ｊｆｅスチール株式会社 高強度熱延鋼板、部材、およびそれらの製造方法

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015019557A1 (ja) * 2013-08-09 2015-02-12 Ｊｆｅスチール株式会社 高降伏比高強度冷延鋼板およびその製造方法
JP2017214647A (ja) 2016-05-30 2017-12-07 株式会社神戸製鋼所 高強度鋼板およびその製造方法
JP2018021233A (ja) 2016-08-03 2018-02-08 株式会社神戸製鋼所 高強度鋼板およびその製造方法
JP2018021231A (ja) 2016-08-03 2018-02-08 株式会社神戸製鋼所 高強度鋼板およびその製造方法
WO2018147400A1 (ja) * 2017-02-13 2018-08-16 Ｊｆｅスチール株式会社 高強度鋼板およびその製造方法
WO2019212047A1 (ja) * 2018-05-01 2019-11-07 日本製鉄株式会社 亜鉛系めっき鋼板及びその製造方法
WO2019212045A1 (ja) * 2018-05-01 2019-11-07 日本製鉄株式会社 亜鉛系めっき鋼板及びその製造方法
JP2019534941A (ja) * 2016-10-31 2019-12-05 バオシャン アイアン アンド スティール カンパニー リミテッド 引張強度が１５００ＭＰａ以上で、かつ成形性に優れた冷間圧延高強度鋼及びその製造方法
JP2020509199A (ja) * 2016-12-21 2020-03-26 アルセロールミタル 高成形性を有する高強度冷間圧延鋼板及びその製造方法
WO2022185804A1 (ja) * 2021-03-02 2022-09-09 Ｊｆｅスチール株式会社 鋼板、部材およびそれらの製造方法
WO2022215389A1 (ja) * 2021-04-09 2022-10-13 Ｊｆｅスチール株式会社 高強度冷延鋼板およびその製造方法

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR102121415B1 (ko) * 2016-04-14 2020-06-10 제이에프이 스틸 가부시키가이샤 고강도 강판 및 그의 제조 방법

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015019557A1 (ja) * 2013-08-09 2015-02-12 Ｊｆｅスチール株式会社 高降伏比高強度冷延鋼板およびその製造方法
JP2017214647A (ja) 2016-05-30 2017-12-07 株式会社神戸製鋼所 高強度鋼板およびその製造方法
JP2018021233A (ja) 2016-08-03 2018-02-08 株式会社神戸製鋼所 高強度鋼板およびその製造方法
JP2018021231A (ja) 2016-08-03 2018-02-08 株式会社神戸製鋼所 高強度鋼板およびその製造方法
JP2019534941A (ja) * 2016-10-31 2019-12-05 バオシャン アイアン アンド スティール カンパニー リミテッド 引張強度が１５００ＭＰａ以上で、かつ成形性に優れた冷間圧延高強度鋼及びその製造方法
JP2020509199A (ja) * 2016-12-21 2020-03-26 アルセロールミタル 高成形性を有する高強度冷間圧延鋼板及びその製造方法
WO2018147400A1 (ja) * 2017-02-13 2018-08-16 Ｊｆｅスチール株式会社 高強度鋼板およびその製造方法
WO2019212047A1 (ja) * 2018-05-01 2019-11-07 日本製鉄株式会社 亜鉛系めっき鋼板及びその製造方法
WO2019212045A1 (ja) * 2018-05-01 2019-11-07 日本製鉄株式会社 亜鉛系めっき鋼板及びその製造方法
WO2022185804A1 (ja) * 2021-03-02 2022-09-09 Ｊｆｅスチール株式会社 鋼板、部材およびそれらの製造方法
WO2022215389A1 (ja) * 2021-04-09 2022-10-13 Ｊｆｅスチール株式会社 高強度冷延鋼板およびその製造方法

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP4560038A4

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2026063176A1 (ja) * 2024-09-18 2026-03-26 Ｊｆｅスチール株式会社 高強度鋼板およびその製造方法
WO2026063174A1 (ja) * 2024-09-18 2026-03-26 Ｊｆｅスチール株式会社 高強度鋼板およびその製造方法
JP7845595B1 (ja) * 2024-09-18 2026-04-14 Ｊｆｅスチール株式会社 高強度鋼板およびその製造方法
JP7845596B1 (ja) * 2024-09-18 2026-04-14 Ｊｆｅスチール株式会社 高強度鋼板およびその製造方法
WO2026070560A1 (ja) * 2024-09-26 2026-04-02 Ｊｆｅスチール株式会社 高強度熱延鋼板、部材、およびそれらの製造方法
WO2026070559A1 (ja) * 2024-09-26 2026-04-02 Ｊｆｅスチール株式会社 高強度熱延鋼板、部材、およびそれらの製造方法

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MX2025002002A (es) 2025-04-02
JP7761672B2 (ja) 2025-10-28
US20260071306A1 (en) 2026-03-12
CN119654435A (zh) 2025-03-18
EP4560038A1 (en) 2025-05-28
KR20250044383A (ko) 2025-03-31
EP4560038A4 (en) 2025-11-12

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