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:
Aug. 18, 1987
Filed:
Mar. 14, 1986
Hajime Ogata, Chiba, JP;
Hisatada Nakakouji, Chiba, JP;
Yasuhiro Akeda, Chiba, JP;
Toshio Ichida, Chiba, JP;
Toshio Irie, Chiba, JP;
Sachiko Otsuka, Chiba, JP;
Kawasaki Steel Corporation, Kobe, JP;
Abstract
A tin-free steel strip comprising a steel strip, 40 to 150 mg/m.sup.2 of a metallic chromium layer on the steel surface, and 5 to 25 mg/m.sup.2 of a chromium compound containing layer thereon wherein the metallic chromium layer contains a plurality of protrusions, exhibits improved corrosion resistance and weldability and is thus useful in the manufacture of welded cans. Preferably, 1.times.10.sup.11 to 1.times.10.sup.14 protrusions having a diameter of 5 to 1000 nm at the base thereof are present per square meter of the metallic chromium layer surface. The tin-free steel strip is produced by chromium plating a steel strip in an aqueous solution containing CR.sup.6+ preferably to a weight of 40 to 140 mg/m.sup.2, subjecting the chromium plated strip to anodic electrolysis, preferably at an eectricity quantity of 0.1 to 10 C/dm.sup.2, and subjecting the strip to a cathodic treatment in an aqueous solution containing Cr.sup.6+ and a chromium plating aid so as to deposit additional metallic chromium, preferably in a weight of 10 to 60 mg/m.sup.2.