Title:
HIGH-STRENGTH STEEL SHEET AND METHOD FOR MANUFACTURING SAME
Document Type and Number:
WIPO Patent Application WO/2020/110795
Kind Code:
A1
Abstract:
The purpose is to provide: a high-strength steel sheet having excellent strength-ductility balance and excellent material stability; and a method for manufacturing the high-strength steel sheet. A high-strength steel sheet in which the content of a specific steel composition is limited, and for which the production conditions are optimized, and which has a steel structure comprising ferrite and a hard phase, wherein the area ratio of the ferrite is 30 to 70% inclusive, the hard phase contains bainitic ferrite, tempered martensite, martensite (including 0%) and retained austenite (including 0%), the largest particle diameter dmax of the ferrite is 2.5 μｍ or less, and the ratio of the ferrite area ratio AF to the ferrite average particle diameter dF satisfies the following formula: AF [%]/dF [μｍ] ≧ 15.
Inventors:
TOBATA JUNYA (JP)
MINAMI HIDEKAZU (JP)
KOBAYASHI TAKASHI (JP)
MINAMI HIDEKAZU (JP)
KOBAYASHI TAKASHI (JP)
Application Number:
PCT/JP2019/045019
Publication Date:
June 04, 2020
Filing Date:
November 18, 2019
Export Citation:
Assignee:
JFE STEEL CORP (JP)
International Classes:
C21D9/46; C22C38/00; C22C38/12; C22C38/60
Domestic Patent References:
| WO2016135793A1 | 2016-09-01 |
Foreign References:
| JP2015113475A | 2015-06-22 | |||
| JP2012001773A | 2012-01-05 | |||
| JP2017039973A | 2017-02-23 | |||
| JP2011179050A | 2011-09-15 | |||
| JP2009214164A | 2009-09-24 | |||
| JP2002059209A | 2002-02-26 | |||
| JP2010209428A | 2010-09-24 | |||
| JP2011111671A | 2011-06-09 |
Other References:
See also references of EP 3889277A4
Attorney, Agent or Firm:
KUMASAKA Akira et al. (JP)
Download PDF: