Title:
HIGH-STRENGTH STEEL SHEET AND METHOD FOR PRODUCING SAME
Document Type and Number:
WIPO Patent Application WO/2023/276516
Kind Code:
A1
Abstract:
Provided are a high-strength steel sheet and a method for producing the same. A high-strength steel material according to the present invention has a particular component composition, wherein: the metal structure of the high-strength steel sheet at the 1/4 position in the sheet thickness is constituted by a soft phase which is the main phase and which is constituted by ferrite and a hard phase which is the remainder including one or more of perlite, bainite, and martensite; the fraction of processed ferrite in the entire metal structure is 50% or higher in volume fraction; the aspect ratio of the processed ferrite is 1.5 or more; the average crystal grain size of the processed ferrite is 50 μm or less; the yield stress of a base material is 235 MPa or more; the Charpy impact absorption energy of the base material at -60°C is 200 J or more; and the Charpy impact absorption energy at -60°C in the welding heat-affected zone after high heat input welding is 80 J or more.
Inventors:
ARAO RYO (JP)
TAKESHITA RYUHEI (JP)
TACHIBANA SHUNICHI (JP)
TAKESHITA RYUHEI (JP)
TACHIBANA SHUNICHI (JP)
Application Number:
PCT/JP2022/021867
Publication Date:
January 05, 2023
Filing Date:
May 30, 2022
Export Citation:
Assignee:
JFE STEEL CORP (JP)
International Classes:
C22C38/00; C21D8/02; C22C38/14; C22C38/58
Domestic Patent References:
| WO2021199629A1 | 2021-10-07 |
Foreign References:
| JP2020117779A | 2020-08-06 | |||
| JP2019214752A | 2019-12-19 | |||
| JP2013079444A | 2013-05-02 | |||
| JP2003239036A | 2003-08-27 | |||
| JPH10147845A | 1998-06-02 |
Attorney, Agent or Firm:
KUMASAKA Akira et al. (JP)
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