Patent ID: 6361623
Filing Date: 2002-03-26
Classification: C23C

Abstract:
A method of forming a phosphate conversion coating on a substrate surface of iron or steel, said process comprising operations of:(I) contacting the substrate surface on which a phosphate conversion coating to be formed with a surface conditioning liquid composition that comprises, as dispersed particles, at least one of zinc phosphate, zinc calcium phosphate, calcium phosphate and colloidally dispersed titanium, so as to form a conditioned substrate surface, the surface conditioning liquid composition further comprising from 0.001 to 5.0 g/L of total oxides selected from the group of oxides of silicon, boron, titanium, zirconium, aluminum, lead, magnesium, cerium, zinc, tin, iron, molybdenum, and vanadium; and (II) contacting the conditioned substrate surface provided at the end of operation (I) with a phosphatizing solution that comprises calcium catons.