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. 07, 1986
Filed:
Oct. 23, 1985
Susumu Satoh, Chiba, JP;
Hideo Suzuki, Chiba, JP;
Takashi Obara, Chiba, JP;
Minoru Nishida, Chiba, JP;
Osamu Hashimoto, Chiba, JP;
Kawasaki Steel Corporation, Kobe, JP;
Abstract
A cold rolled dual-phase structure steel sheet having an excellent deep drawability is disclosed, which consists of ferrite phase and low temperature transformation product phase and comprises 0.001-0.008 wt % of C, not more than 1.0 wt % of Si, 0.05-1.8 wt % of Mn, not more than 0.15 wt % of P, 0.01-0.10 wt % of Al, 0.002-0.050 wt % of Nb and 0.0005-0.0050 wt % of B provided that the value of Nb (%)+10B (%) is in a range of 0.010-0.080%, and, if necessary, 0.05-1.00 wt % of Cr and the balance being substantially Fe with inevitable impurities. This steel sheet is manufactured by hot and cold rolling a steel slab with the above chemical composition and continuously annealing the resulting steel sheet in such a manner than the steel sheet is heated and soaked at a temperature from .alpha..fwdarw..gamma. transformation point to 1,000.degree. C. and then cooled at an average cooling rate of not less than 0.5.degree. C./sec but less than 20.degree. C./sec in a temperature range of from the soaking temperature to 750.degree. C., and subsequently at an average cooling rate of not less than 20.degree. C./sec in a temperature range of from 750.degree. C. to not more than 300.degree. C.