Composition and process for the phosphatizing of metals

Abstract

A composition for the phosphatizing of metals, particularly iron and steel, which comprises an aqueous acidic, chlorate-containing zinc phosphate solution which contains from 0.5 to 1.5 g/liter Zn from 0.4 to 1.3 g/liter Ni from 10 to 26 g/liter P.sub.2 O.sub.5 from 0.8 to 5 g/liter Cl0.sub.3 and in which no nitrite is added, and in which the weight ratio of Zn to Ni shall be adjusted to a value of 1: (from 0.5 to 1.5), that of Zn to P.sub.2 O.sub.5 to a value of 1: (from 8 to 85) and that of free P.sub.2 O.sub.5 to a value of from (0.005 (at about 30 degrees C.) to 0.06 (at about 60 degrees C.)): 1. The composition is particularly useful in processes for the preparation of metal surfaces for electrophoretic coating, particularly for cathodic immersion coating.

Dependencies are inferred from the claim text.