COMPOSITION AND PROCESS FOR TREATING A METAL SURFACE

摘要

A process for treating a zinciferous surface that affords an excellent resistance to black tarnishing and an excellent resistance to white rust comprises treating the zinciferous surface with an acidic aqueous solution with a pH of 1.5 to 4.5 that contains at least one type of heavy metal ions selected from iron, cobalt, and nickel and also contains zinc ions and/or aluminum ions, rinsing with water the surface thus treated, and subjecting the thus rinsed surface to a dry-in-place chromate treatment.