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:
Oct. 18, 1994
Filed:
Apr. 24, 1992
Susumu Okada, Chiba, JP;
Kei Sakata, Chiba, JP;
Susumu Satoh, Chiba, JP;
Masahiko Morita, Chiba, JP;
Toshiyuki Kato, Chiba, JP;
Kawasaki Steel Corporation, Kobe, JP;
Abstract
The invention relates to a high strength cold rolled steel sheet having excellent non-aging property at room temperature and excellent drawability, said steel sheet having a dual-phase structure composed of a high-temperature transformed ferrite phase and a low-temperature transformed ferrite phase having high dislocation density. The invention also relates a high strength cold rolled steel sheet having excellent non-aging property at room temperature and bake hardenability, as well as excellent drawability. This steel sheet is produced by preparing a hot-rolled steel sheet, cold rolling the hot-rolled steel sheet at a rolling reduction not smaller than 60%, annealing the cold rolled steel sheet at a temperature which is not lower than the .gamma. transformation start temperature but below the A.sub.c3 transformation temperature, and cooling the annealed steel sheet at a rate not smaller than 5.degree. C./sec but not greater than 100.degree. C./sec.