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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.:

US 12410491 B1

PDFFull Text
Date of Patent:
Sep. 09, 2025

Filed:

Oct. 18, 2019

High-strength steel sheet and method for producing the same

Applicant:

Jfe Steel Corporation, Tokyo, JP;

Inventors:

Lingling Yang, Tokyo, JP;

Tatsuya Nakagaito, Tokyo, JP;

Assignee:

JFE Steel Corporation, Tokyo, JP;

Attorney:

Buchanan Ingersoll & Rooney PC

Primary Examiner:

Sally A Merkling

Assistant Examiner:

Danny N Kang

Int. Cl.
CPC ...
C21D 9/46 (2006.01); 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 38/12 (2006.01); C22C 38/14 (2006.01); C23C 2/06 (2006.01); C23C 2/28 (2006.01); C23C 2/40 (2006.01);
U.S. Cl.
CPC ...
C21D 9/46 (2013.01); C21D 8/0226 (2013.01); C21D 8/0236 (2013.01); C21D 8/0273 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/12 (2013.01); C22C 38/14 (2013.01); C23C 2/06 (2013.01); C23C 2/28 (2013.01); C23C 2/40 (2013.01); C21D 2211/002 (2013.01); C21D 2211/005 (2013.01); C21D 2211/008 (2013.01); C21D 2211/009 (2013.01);
Abstract

A high-strength steel sheet that has a predetermined component composition, that has a steel microstructure in which, in a thickness cross-section in a rolling direction, an area percentage of ferrite ranges from 5% to 30%, a total area percentage of tempered martensite and bainite ranges from 40% to 90%, pearlite constitutes 0% to 5%, a total area percentage of fresh martensite and retained γ ranges from 5% to 30%, a ratio of a total area percentage of the fresh martensite and the retained γ to a total area percentage of the tempered martensite, bainite, and pearlite is 0.5 or less, and a ratio of the fresh martensite and the retained γ adjacent to the ferrite with respect to the fresh martensite and the retained γ is 30% or more in total area percentage, and that has a yield strength of 550 MPa or more.

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