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:
May. 20, 2025
Filed:
Dec. 11, 2018
Nippon Steel Corporation, Tokyo, JP;
Hiroyuki Kawata, Tokyo, JP;
Eisaku Sakurada, Tokyo, JP;
Kohichi Sano, Tokyo, JP;
Takafumi Yokoyama, Tokyo, JP;
NIPPON STEEL CORPORATION, Tokyo, JP;
Abstract
A high-strength steel sheet excellent in formability, toughness and weldability has a chemical composition including: by mass %, C: 0.05 to 0.30%, Si: 2.50% or less, Mn: 0.50 to 3.50%, P: 0.100% or less, S: 0.0100% or less, Al: 0.001 to 2.500%, N: 0.0150% or less, O: 0.0050% or less, and the balance consisting of Fe and inevitable impurities. The high-strength steel sheet has a microstructure in a region from ⅛ t (t: sheet thickness) to ⅜ t (t: sheet thickness) from a steel sheet surface, the microstructure including: by volume %, acicular ferrite (): 20% or more, and martensite (): 10% or more, polygonal ferrite: 20% or less, residual austenite: 2.0% or less, and the martensite satisfies a formula (A),