Title:
STEEL SHEET, MEMBER, METHOD FOR PRODUCING SAID STEEL SHEET AND METHOD FOR PRODUCING SAID MEMBER
Document Type and Number:
WIPO Patent Application WO/2021/085336
Kind Code:
A1
Abstract:
The purpose of the present invention is to provide: a steel sheet having high strength, excellent shape uniformity and excellent delayed fracture resistance; a member; a method for producing this steel sheet; and a method for producing this member. A steel sheet according to the present invention has a steel structure which comprises, in area ratio, from 20% to 100% of martensite, from 0% to 80% of ferrite and 5% or less of other metal phases, wherein the ratio of the dislocation density of the metal phases in the steel sheet surface to the dislocation density of the metal phases in the center part of the steel sheet in the thickness direction is from 30% to 80%; and the maximum amount of warp of the steel sheet is 15 mm or less if the steel sheet is sheared into pieces having a length of 1 m in the rolling direction.
Inventors:
HIRASHIMA TAKUYA (JP)
YOSHIOKA SHIMPEI (JP)
KANEKO SHINJIRO (JP)
YOSHIMOTO SOSHI (JP)
HASHIMUKAI TOMOHIRO (JP)
YOSHIOKA SHIMPEI (JP)
KANEKO SHINJIRO (JP)
YOSHIMOTO SOSHI (JP)
HASHIMUKAI TOMOHIRO (JP)
Application Number:
PCT/JP2020/039951
Publication Date:
May 06, 2021
Filing Date:
October 23, 2020
Export Citation:
Assignee:
JFE STEEL CORP (JP)
International Classes:
C21D9/46; C22C38/00; C22C38/06; C22C38/60
Domestic Patent References:
| WO2019181950A1 | 2019-09-26 | |||
| WO2020026838A1 | 2020-02-06 |
Foreign References:
| JP2017119912A | 2017-07-06 | |||
| JPH08176884A | 1996-07-09 | |||
| JPS462733B1 | 1971-01-23 | |||
| JP2020019992A | 2020-02-06 | |||
| JP2010090432A | 2010-04-22 | |||
| JP6094722B2 | 2017-03-15 |
Other References:
See also references of EP 4015660A4
Attorney, Agent or Firm:
KUMASAKA Akira et al. (JP)
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