Abstract: An organic lubricating coating composition for use in plastic deformation of a metal sheet comprises a maleic anhydride/styrene copolymer which has been at least partially esterified with one or more organic hydroxy compounds, or a salt of the esterified copolymer. The molar ratio of the maleic anhydride component to the styrene component in the copolymer is in the range of from 1:99 to 75:25. At least 10% by weight of the organic hydroxy compounds is comprised of a long-chain hydroxy compound containing from 10 to 30 carbon atoms.

Abstract: A corrosion resistant duplex plated sheet steel is disclosed, which comprises a sheet steel having on at least one surface thereof a lower layer of Zn base alloy plating and an upper layer thereon selected from a zinc plating having a coating weight of 0.1-5 g/m.sup.2 and a zinc alloy or zinc composite plating having a coating weight of 0.1-10 g/m.sup.2. The ratio of the coating weight of the lower layer to that of the upper layer is at least 1:1 and in the case of upper layer of zinc alloy or zinc composite plating, it comprises, on a weight basis as metal, at least 80% Zn, and one or more additives as Zn corrosion inhibitors selected from Ni, Co, Mn, Sn, Ti, Al, Mg and Si. The duplex plated sheet steel is suitable for coating thereon with an electrophoretic coating composition and exhibits excellent cratering resistance in cathodic electrophoretic coating and excellent cosmetic resistance after painting.

Abstract: A process for producing one-side electroplated steel sheet with the non-electroplating side having a high affinity for chemical conversion treatment is disclosed. The process comprises preparing a one-side electroplated steel sheet by applying a cathodic current thereto in an acidic plating bath simultaneously while slightly electroplating the non-electroplating surface thereof with a coating weight of 0.5 to 5 g/m.sup.2 by applying a cathodic current through said non-electroplating surface, and then applying electrolysis to said non-electroplating surface by passing an anodic current through said non-electroplating surface to thoroughly remove said electrodeposition on said non-electroplating surface.