Title:
STEEL SHEET AND PRODUCTION METHOD THEREFOR
Document Type and Number:
WIPO Patent Application WO/2018/062381
Kind Code:
A1
Abstract:
Provided are: a steel sheet that has a TS of 1320 MPa or more and is capable of imparting excellent delayed fracture resistance to a component that is subjected to cold pressing after blanking by shearing or slitting or piercing by punching, or to cold pressing followed by cutting of the component by shearing or piercing by punching; and a production method for the steel sheet. This steel sheet has a predetermined component composition and a steel structure in which the total of martensite and bentonite constitutes 95-100% by area of the entire structure, the balance comprises one or two of ferrite and residual austenite, there are 5/mm2 or less of predetermined inclusion groups, and prior austenite grains have an average grain size of more than 5 µm. The steel sheet has a tensile strength of 1320 MPa or more.
Inventors:
YOSHIOKA SHIMPEI (JP)
ONO YOSHIHIKO (JP)
HIDAKA KENTA (JP)
YAMAGUCHI RYOSUKE (JP)
ONO YOSHIHIKO (JP)
HIDAKA KENTA (JP)
YAMAGUCHI RYOSUKE (JP)
Application Number:
PCT/JP2017/035200
Publication Date:
April 05, 2018
Filing Date:
September 28, 2017
Export Citation:
Assignee:
JFE STEEL CORP (JP)
International Classes:
C22C38/00; C21D9/46; C22C38/14; C22C38/58
Domestic Patent References:
| WO2015174530A1 | 2015-11-19 |
Foreign References:
| JP2015151576A | 2015-08-24 | |||
| JP2012197506A | 2012-10-18 | |||
| JPS514276B1 | 1976-02-10 | |||
| JPS5428705B2 | 1979-09-18 | |||
| JPS5431019A | 1979-03-07 | |||
| JPS5824401B2 | 1983-05-20 | |||
| JP4427010B2 | 2010-03-03 |
Other References:
See also references of EP 3486346A4
Attorney, Agent or Firm:
KUMASAKA Akira et al. (JP)
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