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:
Oct. 18, 2022
Filed:
Mar. 19, 2019
Nippon Steel Corporation, Tokyo, JP;
Takuya Nishio, Tokyo, JP;
Kojiro Akiba, Tokyo, JP;
Yoshimasa Narita, Tokyo, JP;
Kotaro Ohno, Tokyo, JP;
Satoshi Kato, Tokyo, JP;
Masafumi Azuma, Tokyo, JP;
NIPPON STEEL CORPORATION, Tokyo, JP;
Abstract
This high-strength cold-rolled steel sheet has a predetermined chemical composition, wherein a microstructure at a ¼ position of a sheet thickness from a surface includes predetermined ranges of volume percentages of tempered martensite, residual austenite, ferrite and bainite, and martensite, wherein a microstructure at a position 25 μm from the surface includes, predetermined ranges of volume percentage of ferrite and bainite, and martensite and tempered martensite, wherein in the position 25 μm from the surface, an average grain size of the martensite and the tempered martensite is 5.0 μm or less, a tensile strength is 1,310 MPa or more, and a uniform elongation is 5.0% or more, and R/t is 5.0 or less, the R/t being a ratio of a limit bend radius R in 90° V-bending to a sheet thickness t.