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. 02, 2025
Filed:
Aug. 18, 2020
Applicant:
Jfe Steel Corporation, Tokyo, JP;
Inventors:
Assignee:
JFE STEEL CORPORATION, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C21D 8/02 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/26 (2006.01); C22C 38/28 (2006.01);
U.S. Cl.
CPC ...
C22C 38/04 (2013.01); C21D 8/0226 (2013.01); C21D 8/0263 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/02 (2013.01); C22C 38/06 (2013.01); C22C 38/26 (2013.01); C22C 38/28 (2013.01); C21D 2211/001 (2013.01);
Abstract
The steel of the present disclosure contains, in mass %, C: 0.100% to 0.700%, Si: 0.05% to 1.00%, Mn: 20.0% to 40.0%, P: ≤0.030%, S: ≤0.0050%, Al: 0.01% to 5.00%, Cr: 0.5% to 7.0%, N: 0.0050% to 0.0500%, O: ≤0.0050%, Ti: ≤0.005%, Nb: ≤0.005%, and at least one selected from Ca: 0.0005% to 0.0100%, Mg: 0.0005% to 0.0100%, and REM: 0.0010% to 0.0200%, and has a microstructure with austenite as matrix, where an average grain size is 50 μm or less, a cleanliness of sulfide inclusion is less than 1.0%, a yield strength is 400 MPa or more, and a percent brittle fracture after a Charpy impact test at −269° C. is less than 5%.