Phosphating process of metal surface

摘要

A process for phosphating a metal surface to be electrocoated, which comprises treating the metal surface with an acidic phosphating solution comprising a zinc compound in a concentration of 0.5 to 1.5 g/l as zinc ion, a phosphate in a concentration of 5 to 30 g/l as phosphate ion and a nitrite in a concentration of 0.01 to 0.2 g/l as nitrite ion and/or an aromatic nitro compound in a concentration of 0.05 to 2 g/l in water at a temperature of 40 to 70 DEG C. first by dipping for not less than 15 seconds and then by spraying for not less than 2 seconds.