Title:
STEEL SHEET, MEMBER AND METHODS FOR PRODUCING THESE
Document Type and Number:
WIPO Patent Application WO/2023/162205
Kind Code:
A1
Abstract:
The present invention provides: a steel sheet which has excellent material uniformity and high strength; a member; a method for producing this steel sheet; and a method for producing this member. The present invention provides a steel sheet which has a component composition that contains, in mass%, 0.10% to 0.30% of C, 0.01% to 3.0% of Si, 1.0% to 3.5% of Mn, 0.002% to 0.100% of P, 0.0002% to 0.0200% of S, 0.20% or less (excluding 0%) of sol. Al, 0.010% or less of N and 0.008% to 0.10% of Ti, with the balance being made up of Fe and unavoidable impurities, while having a steel sheet structure that comprises, in area ratios, 5% to 50% of ferrite and 50% to 95% of martensite and bainite in total. With respect to this steel sheet, the area ratio of non-recrystallized ferrite among the ferrite is 0% to 10% relative to the whole structure; and the difference between the maximum value and the minimum value of the area ratio of non-recrystallized ferrite in the sheet width direction of the steel sheet is 5% or less.
Inventors:
HATA KATSUYA (JP)
NAKAGAITO TATSUYA (JP)
NAKAGAITO TATSUYA (JP)
Application Number:
PCT/JP2022/008224
Publication Date:
August 31, 2023
Filing Date:
February 28, 2022
Export Citation:
Assignee:
JFE STEEL CORP (JP)
International Classes:
C21D9/46; C22C38/00; C23C2/06; C23C2/28
Domestic Patent References:
| WO2021020439A1 | 2021-02-04 | |||
| WO2016031166A1 | 2016-03-03 |
Attorney, Agent or Firm:
KUMASAKA Akira et al. (JP)
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