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:
Mar. 16, 2010
Filed:
Dec. 09, 2003
Toshiyuki Katsumi, Kimitsu, JP;
Kazuhiko Honda, Kimitsu, JP;
Koki Tanaka, Futtsu, JP;
Kaoru Yamazaki, Tokyo, JP;
Takahiro Tanae, Wako, JP;
Katsuyoshi Kaneko, Wako, JP;
Yoshikazu Umeno, Wako, JP;
Yoshitaka Okitsu, Wako, JP;
Toshiyuki Katsumi, Kimitsu, JP;
Kazuhiko Honda, Kimitsu, JP;
Koki Tanaka, Futtsu, JP;
Kaoru Yamazaki, Tokyo, JP;
Takahiro Tanae, Wako, JP;
Katsuyoshi Kaneko, Wako, JP;
Yoshikazu Umeno, Wako, JP;
Yoshitaka Okitsu, Wako, JP;
Nippon Steel Corporation, Tokyo, JP;
Honda Motor Co., Ltd., Tokyo, JP;
Abstract
The present invention: provides a good-workability and high-strength cold-rolled steel sheet excellent in post-painting corrosion resistance to the extent of securing excellent resistance to salt warm water immersion which is a good-workability and high-strength cold-rolled steel sheet excellent in post-painting corrosion resistance characterized in that: said steel sheet contains, in mass, 0.16 to 0.19% C, 1.10 to 1.30% Si, 1.50 to 1.60% Mn, not more than 0.1% P and 0.015 to 0.050% Al, with the balance consisting of Fe and unavoidable impurities; the average of the amount of Si incrassating on the surface of said steel sheet is not more than 20 times the Si concentration in said steel sheet; and the area percentage of the portions where the ratio of the Si concentration on the surface of said steel sheet to the Si concentration in said steel sheet is not less than 10 is not more than 95%.