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. 28, 1993
Filed:
Apr. 13, 1993
Kazuhiro Hasegawa, Chiba, JP;
Hiroki Nakamaru, Chiba, JP;
Kazuo Mochizuki, Chiba, JP;
Tomokatsu Katagiri, Chiba, JP;
Nobuyuki Morito, Chiba, JP;
Shigeo Kurokawa, Chiba, JP;
Kawasaki Steel Corporation, , JP;
Abstract
The present invention provides a method of producing a zinc-chromium alloy-plated steel sheet having excellent properties such as bare corrosion resistance, corrosion resistance after coating, plating adhesiveness and weldability. The method is characterized by plating the surface of the steel sheet using an acid plating bath containing zinc ion (Zn.sup.2+) and chromium ion (Cr.sup.3+) at a molar concentration ratio of about 0.1.ltoreq.Cr.sup.3+ /(Zn.sup.3+ +Cr.sup.3+).ltoreq.0.9 in a total amount of at least about 0.5 mol/1 within the dissolution range, and about 0.1 to 30 g/1 of at least one nonionic organic additive having at least a triple bond, at a bath temperature of about 25.degree. to 70.degree. C. and a pH of about 1.0 to 4.0 with a current density of about 50 to 200 A/dm.sup.2.