Patent ID: 9506151
Filing Date: 2016-11-29
CPC Classification: C23C

Claim Text:
1. A method comprising applying a manganese phosphate layer to an iron or steel surface of a workpiece by contacting the iron or steel surface with a phosphating solution at a temperature of from 75 to 95° C., wherein the phosphating solution comprises: 11.8 g/l of manganese ions; 0.5 g/l nickel, 1 g/l of iron (II) ions; 36 g/l of phosphate ions calculated as P 4.6 g/l of nitrate ions; and 0.36 g/l of citrate calculated as citric acid, and drying the workpiece is to form a manganese phosphate layer on said surface, wherein said manganese phosphate layer has a minimum thickness of 3 to 4 microns and an average maximum roughness depth (R z ) of from 1.3 to 2.4 microns; and wherein the phosphating solution is prepared by mixing 183 grams of a concentrate solution to one liter of water, wherein the concentrate solution comprises: 6.45 wt. % of manganese, 0.28 wt of nickel, 0.05 wt. % of iron (II), 19.8 wt. % of P