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. 05, 2013
Filed:
Mar. 13, 2007
Nobuko Mineji, Tokyo, JP;
Eiko Yasuhara, Tokyo, JP;
Reiko Sugihara, Tokyo, JP;
Tadashi Inoue, Tokyo, JP;
Nobuko Mineji, Tokyo, JP;
Eiko Yasuhara, Tokyo, JP;
Reiko Sugihara, Tokyo, JP;
Tadashi Inoue, Tokyo, JP;
JFE Steel Corporation, , JP;
Abstract
A cold-rolled steel sheet has a composition containing, by mass percent, 0.0040% or less of C, 0.02% or less of Si, 0.14% to 0.25% of Mn, 0.020% or less of P, 0.015% or less of S, 0.0040% or less of N, 0.020% to 0.070% of Al, 0.005% to 0.030% of Nb, 0.005% to 0.030% of Ti, (0.0003% to 0.0010% of the equivalent amount of solid solution B (from which the amount of B forming BN has been subtracted)), and the balance composed of Fe and inevitable impurities, wherein even when the rolling reduction of cold rolling is 85% or less, the average grain size of a ferrite structure is reliably 12.0 μm or less, and the relationship −0.20≦Δr≦0.20 can be reliably satisfied and which has an excellent earing property.