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US 2026/0234770 A1Published application
Hot-stamp formed body and aluminum-coated steel sheet for hot stamping
AssigneeNippon Steel Corporation
InventorsKazuhisa KUSUMI, Soshi FUJITA, Yuki SUZUKI, Shinichiro TABATA, Hideaki IRIKAWA, Haruhiko EGUCHI
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Abstract
Adopted are an aluminum-coated steel sheet for hot stamping including a steel sheet, an Fe—Al—Si alloy layer provided onto the steel sheet, and an Al-based coating layer provided onto the Fe—Al—Si alloy layer, in which a Cu content in the Fe—Al—Si alloy layer satisfies Expression (4) (Cui≤0.4×Cu0), and a hot-stamp formed part that can be produced using the aluminum-coated steel sheet for hot stamping.
Claims4
A hot-stamp formed body comprising:
- a steel sheet;
- a diffusion layer provided onto the steel sheet;
- and
- an Fe—Al alloy layer provided onto the diffusion layer,
- wherein a chemical composition of the steel sheet comprises, by mass %,
- C:
- 0.050% to 0.250%,
- Si:
- 0.010% to 2.000%,
- Mn:
- 0.80% to 3.00%,
- P:
- 0.100% or less,
- S:
- 0.0100% or less,
- Al:
- 0.001% to 0.500%,
- N:
- 0.0001% to 0.0150%,
- O:
- 0.1000% or less,
- Ti:
- 0.005% to 0.100%,
- B:
- 0.0005% to 0.0050%,
- Cu:
- 0.050% to 3.000%,
- As:
- 0.0005% to 1.0000%,
- Cr:
- 0% to 1.000%,
- Mo:
- 0% to 1.000%,
- Ni:
- 0% to 3.000%,
- Co:
- 0% to 0.5000%,
- W:
- 0% to 3.0000%,
- Sn:
- 0% to 0.5000%,
- Nb:
- 0% to 0.1000%,
- V:
- 0% to 0.100%,
- Zr:
- 0% to 0.100%,
- Ca:
- 0% to 0.0050%,
- Mg:
- 0% to 0.0050%,
- REM:
- 0% to 0.0050%,
- Sb:
- 0% to 0.0200%,
- Pb:
- 0% to 0.0100%, and
- a remainder comprising Fe and impurities,
- a microstructure of the steel sheet comprises, by area %,
- 90.0% to 100.0% of martensite,
- 0.0% to 3.0% of residual austenite, and
- 0.0% to 10.0% in total of one or more of ferrite, pearlite, bainite, and cementite,
- a chemical composition of the diffusion layer comprises, by mass %,
- Al:
- more than 0.5% and less than 20.0%,
- Fe:
- more than 80.0% and less than 99.5%, and
- Si:
- 0.0% to 15.0%,
- a Cu concentration in the diffusion layer satisfies Expressions (1) and (2),
- an average thickness of the diffusion layer satisfies Expression (3), and
- the Fe—Al alloy layer includes an Fe—Al phase having an Fe content of 40 to 60 mass % by mass % and an Al content of 40% to 60% by mass %,
- 0.025
- ≤
- Cu
- d
- ,
- (
- 1
- )
- Cu
- m
- <
- Cu
- d
- <
- Cu
- 0
- ,
- and
- (
- 2
- )
- 2.
- ≤
- T
- d
- ≤
- 0
- .
- 8
- ×
- (
- T
- d
- +
- T
- m
- )
- ,
- (
- 3
- )
- in Expressions (1) and (2), Cud denotes a Cu concentration in the diffusion layer by atom %, Cum denotes a Cu concentration in the Fe—Al phase in the Fe—Al alloy layer by atom %, and Cu0 denotes a Cu concentration in the steel sheet by atom %, and
- in Expression (3), Td denotes an average thickness in μm of the diffusion layer, and Tm denotes an average thickness in μm of the Fe—Al alloy layer.
112 more elements
An aluminum-coated steel sheet for hot stamping comprising:
- a steel sheet;
- an Fe—Al—Si alloy layer provided onto the steel sheet;
- and
- an Al-based coating layer provided onto the Fe—Al—Si alloy layer,
- wherein a chemical composition of the steel sheet comprises, by mass %,
- C:
- 0.050% to 0.250%,
- Si:
- 0.010% to 2.000%,
- Mn:
- 0.80% to 3.00%,
- P:
- 0.100% or less,
- S:
- 0.0100% or less,
- Al:
- 0.001% to 0.500%,
- N:
- 0.0001% to 0.0150%,
- O:
- 0.1000% or less,
- Ti:
- 0.005% to 0.100%,
- B:
- 0.0005% to 0.0050%,
- Cu:
- 0.050% to 3.000%,
- As:
- 0.0005% to 1.0000%,
- Cr:
- 0% to 1.000%,
- Mo:
- 0% to 1.000%,
- Ni:
- 0% to 3.000%,
- Co:
- 0% to 0.5000%,
- W:
- 0% to 3.0000%,
- Sn:
- 0% to 0.5000%,
- Nb:
- 0% to 0.1000%,
- V:
- 0% to 0.100%,
- Zr:
- 0% to 0.100%,
- Ca:
- 0% to 0.0050%,
- Mg:
- 0% to 0.0050%,
- REM:
- 0% to 0.0050%,
- Sb:
- 0% to 0.0200%,
- Pb:
- 0% to 0.0100%, and
- a remainder comprising Fe and impurities,
- a microstructure of the steel sheet comprises, by area %,
- 20% to 95% of ferrite, and
- 5% to 80% in total of one or more of martensite, bainite, pearlite, and cementite,
- a Cu concentration in the Fe—Al—Si alloy layer satisfies Expression (4), and
- a chemical composition of the Al-based coating layer comprises, by mass %,
- Al
- :
- 85.
- %
-
- to
- 95.
- %
- ,
- and
-
- Si
- :
- 5.
- %
-
- to
- 15.
- %
- ,
- Cu
- i
- ≤
- 0.4
- ×
- Cu
- 0
- ,
- (
- 4
- )
- in Expression (4), Cui denotes a Cu concentration in the Fe—Al—Si alloy layer by atom %, and Cu0 denotes a Cu concentration in the steel sheet by atom %.
92 more elements
Dependencies are inferred from the claim text.