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. 30, 1983
Filed:
Mar. 05, 1981
Toyo Seikan Kaisha Ltd., Tokyo, JP;
Abstract
Disclosed is a process for the preparation of welded cans, which comprises forming a blank into a cylinder and passing a lap portion of the formed cylinder between a pair of electrode rollers through an electrode wire to effect electric resistance welding, wherein said blank is a tin-free steel blank comprising a steel plate substrate, a layer of metallic chromium formed on the surface of the steel plate substrate and a layer of chromium oxide formed on the metallic chromium layer, and electric resistance welding is carried out in an inert atmosphere in the state where an electrode wire having a plated layer of a soft metal selected from the group consisting of tin and alloys thereof, the thickness of said plated layer being 0.1 to 20 .mu.m, is kept in close contact with the chromium oxide layer of the tin-free steel blank. The inner and outer surfaces of the side seam of a welded can according to this process are covered with a continuous or discontinuous protecting covered layer including a metallic chromium layer and a chromium oxide layer formed thereon, and the thickness of steel oxide exposed through this discontinuous portion is controlled below 400 A. Since exposure of steel in the inner and outer surfaces of the seam is thus controlled, the corrosion resistance, lacquer adhesion and appearance charcteristics of the seam are highly improved in this welded can.