Title:
STEEL SHEET
Document Type and Number:
WIPO Patent Application WO/2020/255993
Kind Code:
A1
Abstract:
This steel sheet has a predetermined chemical composition, wherein: a ratio Mn/Ni of Mn content to Ni content is at most 0.80; the carbon equivalent CeqWES is at least 0.43-0.53%, as calculated according to the following equation, CeqWES=C+Mn/6+Si/24+Ni/40+Cr/5+Mo/4+V/14; the tensile strength is 780-930 MPa or less; the yield strength is 630-750 MPa; the yield ratio is at most 85%; the sheet thickness is 40-120 mm; and Hvmin/Hvmax is at most 0.85, when Vickers hardness is measured at a position 1/4 of the sheet thickness from the surface of the steel sheet, the average value of the values ascending from the smallest Vickers hardness to 20% is Hvmin, and the average value of the values descending from the largest Vickers hardness to 20% is Hvmax.
Inventors:
KOJIMA AKIHIKO (JP)
YOSHIMURA NOBUYUKI (JP)
TANAKA SHUN (JP)
YOSHIMURA NOBUYUKI (JP)
TANAKA SHUN (JP)
Application Number:
PCT/JP2020/023693
Publication Date:
December 24, 2020
Filing Date:
June 17, 2020
Export Citation:
Assignee:
NIPPON STEEL CORP (JP)
International Classes:
C22C38/00; C22C38/54; C21D8/02
Foreign References:
| JP2012172243A | 2012-09-10 | |||
| JP2013091845A | 2013-05-16 | |||
| JP2013194316A | 2013-09-30 | |||
| CN104046898A | 2014-09-17 | |||
| JP2017190481A | 2017-10-19 | |||
| JP2019119934A | 2019-07-22 |
Attorney, Agent or Firm:
TANAI Sumio et al. (JP)
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