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:
Sep. 15, 2026
Filed:
Feb. 28, 2022
Jfe Steel Corporation, Tokyo, JP;
JFE STEEL CORPORATION, Tokyo, JP;
Abstract
To provide a steel sheet with a tensile strength of 1310 MPa or more that can achieve excellent press formability in a steel having a martensite-dominant microstructure with excellent delayed fracture resistance properties. Disclosed is a steel sheet including: a chemical composition containing, by mass %, C: 0.12-0.40%, Si: 1.5% or less, Mn: 1.7% or less, P: 0.05% or less, S: 0.010% or less, sol.Al: 1.00% or less, N: 0.010% or less, Ti: 0.002-0.080%, and B: 0.0002-0.0050%, with the balance being Fe and inevitable impurities; a metallic structure in which an area ratio of martensite to an entire microstructure is 95% or more, and a ratio L/Lsatisfies a predetermined formula (1), where Ldenotes a length of a sub-block boundary and Ldenotes a length of a block boundary; and a tensile strength of 1310 MPa or more.