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:
May. 14, 1996
Filed:
May. 04, 1994
The Furukawa Electric Co., Ltd., Tokyo, JP;
Abstract
A method for manufacturing an aluminum alloy sheet for use in a body panel material, comprising: (a) casting a melted aluminum alloy containing Al, Mg, Fe, Mn, Cr, Ti and Zr, having a Mg content of 4 to 10 weight %, and having contents of Fe, Mn, Cr, Ti and Zr which are determined by a value f satisfying the following equation (I), and the balance being Al: 0.4 wt %.ltoreq.f.ltoreq.1.5 wt % (I), wherein, f=(Fe)+1.1 (Mn)+1.1 (Cr)+3 (Ti)+3 (Zr), wherein (Fe), (Mn), (Cr), (Ti), and (Zr) respectively represent the percentage content by weight of Fe, Mn, Cr, Ti and Zr, to form an ingot; (b) hot rolling the ingot to obtain a hot rolled sheet; (c) cold rolling the hot rolled sheet at a cold reduction R satisfying the following equation (II): -log(f-0.2)+8.ltoreq.R.ltoreq.-60 log (f-0.2)+50 (II) to obtain a cold rolled sheet; (d) subjecting the cold rolled sheet to a final annealing treatment including raising the temperature of the rolled sheet to 450.degree. to 550.degree. C. at a rate of 100.degree. C./minute or more, and maintaining the attained temperature for 300 seconds or less; and (e) cooling the annealed rolled sheet at a cooling rate of 100.degree. C./minute or more to obtain an aluminum alloy sheet having a grain size of 20 and 80 .mu.m.