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:
Jul. 17, 2018
Filed:
May. 16, 2014
Nippon Steel & Sumitomo Metal Corporation, Tokyo, JP;
Hiroshi Shuto, Tokyo, JP;
Masafumi Azuma, Tokyo, JP;
Akifumi Sakakibara, Tokyo, JP;
Yuuki Kanzawa, Tokyo, JP;
Ken Kimura, Tokyo, JP;
NIPPON STEEL & SUMITOMO METAL CORPORATION, Tokyo, JP;
Abstract
A hot-rolled steel sheet has a composition containing: in mass %, C: 0.01 to 0.2%; Si: 2.5% or less; Mn: 4.0% or less; P: 0.10% or less; S: 0.03% or less; Al: 0.001 to 2.0%; N: 0.01% or less; and O: 0.01% or less, and one kind or a total of two kinds of Ti and Nb for 0.01 to 0.30%. An average effective crystal grain diameter at a sheet thickness ¼ part is 10 μm or less, and an average effective crystal grain diameter at a part of a range of 50 μm from a surface is 6 μm or less. A structure of the steel sheet is tempered martensite or lower bainite, and a volume fraction thereof is 90% or more as a total.