Surface-treated metal material excelllent in resistance against galvanic corrosion and joined article of dissimilar materials including the surface-treated metal material

摘要

Disclosed is a surface-treated metal material which includes a metallic base including a steel or aluminum material; and an anti-corrosive layer present covering at least one surface of the metallic base. The anti-corrosive layer contains 0.001 to 1 g/m² of one or more substances selected from the group consisting of benzoic acid salts, glutamic acid salts, anisidines, glycine, and quinolinols. The benzoic acid salts and/or glutamic acid salts are preferably chosen from potassium salt, sodium salt and ammonium salt. Also disclosed is a joined article of dissimilar materials including the surface-treated metal material as at least one of the materials. The surface-treated metal material includes, as the base metal, a steel or aluminum material and is thereby effectively and inexpensively protected from galvanic corrosion without performing electrical insulation or complete atmospheric isolation.