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. 22, 2020
Filed:
Mar. 23, 2016
Jfe Steel Corporation, Tokyo, JP;
Yoshihiko Ono, Tokyo, JP;
Yoshimasa Funakawa, Tokyo, JP;
Ryosuke Yamaguchi, Tokyo, JP;
Nobuyuki Nakamura, Tokyo, JP;
JFE STEEL CORPORATION, Tokyo, JP;
Abstract
A cold-rolled steel sheet has: a predetermined chemical composition; and a microstructure in which tempered martensite and bainite are contained in a total area ratio of 95-100% with respect to a whole volume of the microstructure; a number of predetermined inclusion groups is at most 0.8/mm, the inclusion groups being formed by one or more inclusion particles, the one or more inclusion particles having a major axis length of 0.3 μm or more and extending and/or distributed in a dot-sequence manner along a rolling direction; a number of carbides mainly composed of Fe having a predetermined size is at most 3,500/mm; a number of carbides that are distributed in the tempered martensite and/or in the bainite and that have a diameter of 10 nm to 50 nm is at least 0.7×10/mm; and prior γ grains have a mean grain size of 18 μm or less.