Abstract: Aqueous compositions and low temperature processes for treating clean steel and galvanized steel to provide a coating suitable for the application of paint thereto. The aqueous treating compositions contain:______________________________________ Ingredient Quantity ______________________________________ zinc ion from about 0.9 to about 2.5 g/l; nickel ion from about 0.6 to about 2.0 g/l; orthophosphoric acid from about 15 to about 45 g/l; nitrate ion from about 1.0 to about 10.0 g/l. ______________________________________The pH of the composition is adjusted to 3.0-3.5 by addition of alkali metal hydroxide. The above composition is used on clean galvanized steel. For clean ungalvanized steel, from about 0.10 to about 0.65 g/l of nitrite ion is included in the composition. Optional ingredients in the above compositions include chlorate ion, ferric ion, and a fluoride compound.

Abstract: Aqueous compositions and low temperature processes for treating clean steel and galvanized steel to provide a coating suitable for the application of paint thereto. The aqueous treating compositions contain:______________________________________ Ingredient Quantity ______________________________________ zinc ion from about 0.9 to about 2.5 g/l; nickel ion from about 0.6 to about 2.0 g/l; orthophosphoric acid from about 15 to about 45 g/l; nitrate ion from about 1.0 to about 10.0 g/l. ______________________________________The pH of the composition is adjusted to 3.0-3.5 by addition of alkali metal hydroxide. The above composition is used on clean galvanized steel. For clean ungalvanized steel, from about 0.10 to about 0.65 g/l of nitrite ion is included in the composition. Optional ingredients in the above compositions include chlorate ion, ferric ion, and a fluoride compound.