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:
Jul. 08, 2008
Filed:
May. 02, 2003
Saiji Matsuoka, Okayama, JP;
Tetsuo Shimizu, Okayama, JP;
Kei Sakata, Chiba, JP;
Osamu Furukimi, Chiba, JP;
Saiji Matsuoka, Okayama, JP;
Tetsuo Shimizu, Okayama, JP;
Kei Sakata, Chiba, JP;
Osamu Furukimi, Chiba, JP;
JFE Steel Corporation, , JP;
Abstract
The present invention provides a steel sheet having a chemical composition comprising 0.15% or less C, 2.0% or less Si, 3.0% or less Mn, P, S, A1 and N in adjusted amounts, from 0.5 to 3.0% Cu, or one or more of Cr, Mo and W in a total amount of 2.0% or less, and having a composite structure comprising ferrite and martensite having an area ratio of 2% or more. The steel sheet is in the form of a high-strength hot-rolled steel sheet, a high-strength cold-rolled steel sheet, or a hot-dip galvanized steel sheet. There is thus available a steel sheet excellent in press-formability and in strain age hardening property as represented by a ΔTS of 80 MPa or more.