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. 16, 2017
Filed:
Jun. 15, 2009
Kenichi Yamamoto, Tokyo, JP;
Katsuhiro Sasai, Tokyo, JP;
Hideaki Yamamura, Tokyo, JP;
Hiroshi Harada, Tokyo, JP;
Kaoru Kawasaki, Tokyo, JP;
Kenichi Yamamoto, Tokyo, JP;
Katsuhiro Sasai, Tokyo, JP;
Hideaki Yamamura, Tokyo, JP;
Hiroshi Harada, Tokyo, JP;
Kaoru Kawasaki, Tokyo, JP;
NIPPON STEEL & SUMITOMO METAL CORPORATION, Tokyo, JP;
Abstract
A high-strength steel sheet includes: 0.03 to 0.20% of C, 0.08 to 1.5% of Si, 0.5 to 3.0% of Mn, 0.05% or less of P, 0.0005% or more of S, 0.008 to 0.20% of acid-soluble Ti, 0.0005 to 0.01% of N, more than 0.01% of acid-soluble Al, and 0.001 to 0.04% of one or both of Ce and La in terms of mass %; and the balance including Fe and inevitable impurities. The ratio of (Ce+La)/acid-soluble Al is equal to or more than 0.1 and the ratio of (Ce+La)/S is in the range of 0.4 to 50 in a mass base, and the density of the number of inclusions, having a circle equivalent diameter of 2 μm or less, which are present in the steel sheet is equal to or more than 15/mm.