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:
Aug. 09, 2016
Filed:
Jan. 31, 2011
Riki Okamoto, Tokyo, JP;
Natsuko Sugiura, Tokyo, JP;
Kohichi Sano, Tokyo, JP;
Chisato Wakabayashi, Tokyo, JP;
Naoki Yoshinaga, Tokyo, JP;
Kaoru Kawasaki, Tokyo, JP;
Riki Okamoto, Tokyo, JP;
Natsuko Sugiura, Tokyo, JP;
Kohichi Sano, Tokyo, JP;
Chisato Wakabayashi, Tokyo, JP;
Naoki Yoshinaga, Tokyo, JP;
Kaoru Kawasaki, Tokyo, JP;
NIPPON STEEL & SUMITOMO METAL CORPORATION, Tokyo, JP;
Abstract
A steel sheet, including: as chemical components, by mass %, 0.05% to 0.35% of C; 0.05% to 2.0% of Si; 0.8% to 3.0% of Mn; 0.01% to 2.0% of Al; equal to or less than 0.1% of P; equal to or less than 0.05% of S; equal to or less than 0.01% of N; and the balance including iron and inevitable impurities, wherein the steel sheet comprises 50% or more of a ferrite phase, a bainite phase, and a tempered martensite phase, 3% or more of a retained austenite phase, and 50% or more of the crystal grains of the retained austenite phase satisfy Expression 1, wherein a carbon concentration at a position of center of gravity is Cgc and a carbon concentration at a grain boundary is Cgb.