SURFACE TREATED STEEL SHEET HAVING EXCELLENT CORROSION RESISTANCE AND BLACKING RESISTANCE AND MANUFACTURING METHOD THEREOF

摘要

PROBLEM TO BE SOLVED: To provide a surface treated steel sheet using a galvanized steel sheet as a base material and having excellent corrosion resistance and blackening resistance. SOLUTION: The surface treated steel sheet has a reaction layer of zinc with S or a S-adsorbing layer in which the deposited quantity of S is 0.010-100 mg/m2on a plated film surface layer of the galvanized steel sheet and a chemical conversion layer, preferably a chemical conversion layer formed by a cathode electrolytic treatment and containing a vanadic compound and silica thereon. Because zinc in the reaction layer of zinc with S or the S-adsorbing layer formed on the plated film surface layer is in an oxidized state, additional oxidation and the production of zinc oxide are suppressed to improve the blacking resistance and further the corrosion reaction is suppressed to improve the corrosion resistance as the result of that the reaction layer of zinc with S or the S-adsorbing layer suppress the oxidation. COPYRIGHT: (C)2003,JPO