COATED METAL SUBSTRATE HAVING ANHANCED CORROSION RESISTANCE AND PROCESS THEREOF

摘要

A coated metal substrate having enhanced corrosion resistance is formed by protective coating with the coating compsoite composed of resinless top coating layer formed from a composite thermally hardenable due to thin metallic undercoating layer and water proofing coating which involves at least more than one kind of metal among Zn, Ni, Fe, Cr, Al and Co. The above top coating layer involves more than 20mg per 1 ft2 and sixvalent Cr ion giving materials. And this substrate shows enhanced corrosion resistance.