Title:
FRAMEWORK MEMBER
Document Type and Number:
WIPO Patent Application WO/2022/234791
Kind Code:
A1
Abstract:
This framework member is formed by hot-stamping a steel plate. The framework member has a closed cross-sectional portion having a closed cross section perpendicular to the lengthwise direction, and the closed cross-sectional portion has at least one flat part having the radius of curvature larger than the maximum external dimension in the cross section. The Vickers hardness of a plate thickness center portion in a reference flat part is 300 Hv or greater, the width of the reference flat part is 2.0 times or less of the effective width, and the standard deviation ratio, which is obtained by dividing the standard deviation of a hardness frequency distribution at a surface layer portion of the reference flat part by the standard deviation of a hardness frequency distribution in the plate thickness center portion of the reference flat part, is smaller than 1.0.
Inventors:
AITOH TAKAHIRO (JP)
TODA YURI (JP)
TODA YURI (JP)
Application Number:
PCT/JP2022/018953
Publication Date:
November 10, 2022
Filing Date:
April 26, 2022
Export Citation:
Assignee:
NIPPON STEEL CORP (JP)
International Classes:
B21D22/20; B21C37/15; B21D22/26; B62D21/15
Domestic Patent References:
| WO2018151322A1 | 2018-08-23 |
Foreign References:
| JP2020153401A | 2020-09-24 | |||
| JP2021078461A | 2021-05-27 | |||
| JP2009286351A | 2009-12-10 |
Attorney, Agent or Firm:
MATSUNUMA Yasushi et al. (JP)
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