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:
Jan. 08, 2019
Filed:
Feb. 25, 2013
Applicant:
Jfe Steel Corporation, Chiyoda-ku, Tokyo, JP;
Inventors:
Assignee:
JFE Steel Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C21D 1/26 (2006.01); C23G 1/08 (2006.01); C21D 9/46 (2006.01); C22C 38/04 (2006.01); C22C 38/58 (2006.01); C22C 38/02 (2006.01); C22C 38/06 (2006.01); C21D 6/00 (2006.01); C21D 8/02 (2006.01); C23F 17/00 (2006.01); B62D 29/00 (2006.01);
U.S. Cl.
CPC ...
C23G 1/086 (2013.01); C21D 6/005 (2013.01); C21D 6/008 (2013.01); C21D 8/0226 (2013.01); C21D 8/0236 (2013.01); C21D 8/0273 (2013.01); C21D 9/46 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/58 (2013.01); C23F 17/00 (2013.01); C23G 1/085 (2013.01); B62D 29/007 (2013.01); C21D 1/26 (2013.01); C21D 2211/002 (2013.01); C21D 2211/005 (2013.01);
Abstract
A Si-containing high-strength cold rolled steel sheet has a chemical composition comprising C: 0.02˜0.3 mass %, Si: 0.8˜2.0 mass %, Mn: 1.0˜5.0 mass % and the remainder being Fe and inevitable impurities with a ratio of Si content to Mn content (Si/Mn) exceeding 0.4, and has a tensile strength TS of not less than 780 MPa, wherein a metallic structure of the steel sheet surface contains polygonal ferrite and/or bainitic ferrite having a Si concentration of not more than 3.0 mass % and a grain size of not more than 10 μm and does not have a Si-containing oxide layer on the steel sheet surface.