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:
Sep. 22, 2009
Filed:
Jan. 28, 2005
Shushi Ikeda, Kobe, JP;
Hiroshi Akamizu, Kobe, JP;
Koichi Makii, Kobe, JP;
Yoichi Mukai, Kakogawa, JP;
Koichi Sugimoto, Ueda, JP;
Shushi Ikeda, Kobe, JP;
Hiroshi Akamizu, Kobe, JP;
Koichi Makii, Kobe, JP;
Yoichi Mukai, Kakogawa, JP;
Koichi Sugimoto, Ueda, JP;
Kabuhsiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.), Kobe-shi, JP;
Abstract
To provide a high strength and low yield ratio cold rolled steel sheet having high elongation property and high flange drawing property, or a plated steel sheet made by plating the same. The high strength and low yield ratio cold rolled steel sheet or the plated steel sheet made by plating the same has such a constitution as 0.10 to 0.25% of C, 1.0 to 2.0% of Si and 1.5 to 3.0% of Mn, are contained in terms of weight percentage, while other elements are controlled such as Al within 0.2%, P within 0.15% and S within 0.02%, with residual austenite occupying at least 5%, bainitic ferrite occupying at least 60% (preferably 80% or more), and polygonal ferrite within 20% (containing 0%), so that a tensile strength is 980 MPa or higher, while an elongation (El in %), a flange drawing property (λin %), a tensile strength (TS in MPa) and a yield strength (YP in MPa) satisfy the following inequality (1): [(El ×λ×TS)/YP]≧645.