The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 19, 2023
Filed:
Sep. 25, 2019
Applicant:
Jfe Steel Corporation, Tokyo, JP;
Inventors:
Assignee:
JFE STEEL CORPORATION, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C21D 9/46 (2006.01); C21D 8/02 (2006.01); C21D 6/00 (2006.01); C22C 38/60 (2006.01); C22C 38/16 (2006.01); C22C 38/14 (2006.01); C22C 38/12 (2006.01); C22C 38/08 (2006.01); C22C 38/06 (2006.01); C22C 38/04 (2006.01); C22C 38/02 (2006.01); C22C 38/00 (2006.01); C22C 38/38 (2006.01); C22C 38/32 (2006.01); C22C 38/28 (2006.01); C22C 38/26 (2006.01); C22C 38/24 (2006.01); C22C 38/22 (2006.01); C22C 38/20 (2006.01);
U.S. Cl.
CPC ...
C21D 9/46 (2013.01); C21D 6/005 (2013.01); C21D 6/008 (2013.01); C21D 8/0205 (2013.01); C21D 8/0226 (2013.01); C21D 8/0236 (2013.01); C21D 8/0263 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/005 (2013.01); C22C 38/008 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/08 (2013.01); C22C 38/12 (2013.01); C22C 38/14 (2013.01); C22C 38/16 (2013.01); C22C 38/20 (2013.01); C22C 38/22 (2013.01); C22C 38/24 (2013.01); C22C 38/26 (2013.01); C22C 38/28 (2013.01); C22C 38/32 (2013.01); C22C 38/38 (2013.01); C22C 38/60 (2013.01); C21D 2211/002 (2013.01); C21D 2211/004 (2013.01); C21D 2211/008 (2013.01);
Abstract
A high-strength steel sheet having high delayed fracture resistance and a method for manufacturing the high-strength steel sheet. The high-strength steel sheet has a specified chemical composition. Relative to the whole microstructure of the steel sheet, the total area fraction of at least one of (i) bainite containing carbide grains having an average grain size of 50 nm or less and (ii) martensite containing carbide grains having an average grain size of 50 nm or less is 90% or more. The average number of inclusions having an average grain size of 5 μm or more that are present in a section of the steel sheet perpendicular to a rolling direction is 5.0/mmor less.