Abstract: Processes and solutions for phosphating metal surfaces. The solutions are acidic aqueous phosphate solutions containing a) from 0.1 to 1.5 g/l of zinc ion; b) from 5 to 50 g/l of phosphate ion; c) from 0.2 to 4 g/l of manganese ion; d) at least 0.05 g/l of fluoride ion; e) less than 0.5 g/l of chloride ion; and f) a phosphating accelerator. The metal surface phosphated with the solution including galvanized steel, is free of white spots and is suitable for electrocoating.

Abstract: Processes and solutions for phosphating metal surfaces. The solutions are acidic aqueous phosphate solutions containing (a) from 0.1 to 1.5 g/l of zinc ion; (b) from 5 to 50 g/l of phosphate ion; (c) from 0.2 to 4 g/l of manganese ion; (d) at least 0.05 g/l of fluoride ion; (e) less than 0.5 g/l of chloride ion; and (f) a phosphating accelerator. The metal surface phosphated with the solution including galvanized steel, is free of white spots and is suitable for electrocoating.

Abstract: Processes and solutions for phosphating metal surfaces. The solutions are acidic aqueous phosphate solutions containing (a) from 0.1 to 1.5 g/l of zinc ion; (b) from 5 to 50 g/l of phosphate ion; (c) from 0.2 to 4 g/l of manganese ion; (d) at least 0.05 g/l of fluoride ion; (e) less than 0.5 g/l of chloride ion; and (f) a phosphating accelerator. The metal surface phosphated with the solution including galvanized steel, is free of white spots and is suitable for electrocoating.

Abstract: A method for enhancing the corrosion resistance of a metal surface at the edge portion which comprises applying direct current to said metal surface as previously zinc phosphated as a negative electrode in an acidic solution comprising zinc ion in a concentration of 2 to 3 g/L, phosphate ion in a concentration of 8 to 14 g/L and chloride ion in a concentration of 3 to 6 g/L under the condition of 5 to 15 A/dm.sup.2 (metal surface) at a temperature of 20.degree. to 40.degree. C. to make an electric zinc phosphate coating film having corrosion resistance.