Title:
STEEL SHEET AND METHOD FOR PRODUCING STEEL SHEET
Document Type and Number:
WIPO Patent Application WO/2023/162893
Kind Code:
A1
Abstract:
This steel sheet contains, in % by mass, 0.15 to 0.50% of C, 0.01 to 1.00% of Si, 1.00 to 3.00% of Mn, 0 to 0.0200% of P, 0.0001 to 0.0200% of S, 0.001 to 0.100% of Al, 0 to 0.0200% of N and a remainder comprising Fe and impurities, in which, with respect to surface area ratios of metal structures, the surface area ratio of retained austenite is 0% to 10% inclusive and the total surface area of pearlite, ferrite and bainite is 0% to 5% inclusive, and in which the remaining structure comprises martensite and tempered martensite, the maximum diameter of MnS is 30 μm or less when determined by extreme value statistics, the surface roughness Ra is 5 μm or less, and the Vickers hardness of a surface layer is a value determined by the formula: (the tensile strength TS (MPa) of the steel sheet)×0.25 or more.
Inventors:
YOKOYAMA TAKAFUMI (JP)
TAKEDA KENGO (JP)
NAKANO KATSUYA (JP)
MIYAKAWA TAKU (JP)
TAKEDA KENGO (JP)
NAKANO KATSUYA (JP)
MIYAKAWA TAKU (JP)
Application Number:
PCT/JP2023/005825
Publication Date:
August 31, 2023
Filing Date:
February 17, 2023
Export Citation:
Assignee:
NIPPON STEEL CORP (JP)
International Classes:
C21D9/46; C22C38/00; C22C38/60
Domestic Patent References:
| WO2021106936A1 | 2021-06-03 | |||
| WO2020045220A1 | 2020-03-05 | |||
| WO2020045219A1 | 2020-03-05 |
Foreign References:
| JP2014201765A | 2014-10-27 |
Attorney, Agent or Firm:
MATSUNUMA Yasushi et al. (JP)
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