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:
Dec. 17, 2002
Filed:
Aug. 03, 2000
Takeshi Fujita, Fukuyama, JP;
Fusato Kitano, Fukuyama, JP;
Yoshihiro Hosoya, Fukuyama, JP;
Toru Inazumi, Fukuyama, JP;
Yuji Yamasaki, Fukuyama, JP;
Masaya Morita, Fukuyama, JP;
Yasunobu Nagataki, Fukuyama, JP;
Kohei Hasegawa, Fukuyama, JP;
Hiroshi Matsuda, Fukuyama, JP;
Moriaki Ono, Fukuyama, JP;
NKK Corporation, Tokyo, JP;
Abstract
The present invention relates to a very low C—Nb cold rolled steel sheet giving 340 to 440 MPa of tensile strength. For example, the cold rolled steel sheet consists essentially of 0.0040 to 0.01% C, not more than 0.05% Si, 0.1 to 1.0% Mn, 0.01 to 0.05% P, not more than 0.02% S, 0.01 to 0.1% sol.Al, not more than 0.004% N, 0.01 to 0.14% Nb, by weight, and balance of substantially Fe and inevitable impurities, and has not less than 0.21 of n value calculated from two points (1% and 10%) of nominal strain determined by the uniaxial tensile test, and relates to a method for manufacturing the cold rolled steel sheet. The present invention provides a high strength cold rolled steel sheet for automobile exterior panels having excellent combined formability, resistance to embrittlement during secondary operation, formability at welded portions, anti-burring performance, good surface appearance, and uniformity of material in a coil.