Aqueous zinc phosphating solution and method of rapid coating of steel for deforming
AssigneeAmchem Products, Inc.
InventorStuart Reed
Life of this patent
Estimating the term…
Abstract
In the continuous strand method of processing high carbon steel wire for subsequent cold deformation, a zinc phosphate conversion coating is rapidly formed on the steel surface to aid in the subsequent deformation by contacting the steel surface with an aqueous acidic coating solution comprising phosphate, zinc and nitrate.
Claims9
A process for forming a zinc phosphate coating on a steel surface comprising contacting the steel surface with an acidic aqueous coating solution consisting essentially of phosphate, zinc and nitrate, wherein the zinc is present in the coating solution in an amount of from about 0.4 to about 1.2 parts by weight for each part of the phosphate and the nitrate is present in the solution in an amount of from about 0.4 to about 1.6 parts by weight for each part of the phosphate, the phosphate being present in the coating solution in an amount of from about 10 g/l to about 150 g/l, the zinc being present in an amount of from about 5 g/l to about 100 g/l, and the nitrate being present in an amount of from about 10 g/l to about 80 g/l and the ratio of total acid to free acid in the coating solution is from about 4.5 to about 8.5 with the total acidity of the coating solution being from about 110 to about 140 points.
A process for forming a zinc phosphate coating on a steel surface comprising:
- acid pickling the steel surface;
- water rinsing the steel surface;
- contacting the steel surface with an acidic aqueous coating solution consisting essentially of phosphate in the amount of from about 10 g/l to about 150 g/l, zinc in the amount of from about 5 g/l to about 100 g/l, and nitrate in the amount of from about 10 g/l to about 80 g/l, and wherein the zinc is present in the coating solution in an amount of from about 0.4 to about 1.2 parts by weight for each part of the phosphate, and the nitrate is present in the solution in an amount from about 0.4 to about 1.6 parts by weight for each part of the phosphate;
- water rinsing the steel surface;
- and
- drying the steel surface.
An acidic aqueous coating solution consisting essentially of phosphate, zinc and nitrate, wherein the phosphate is present in the solution in the amount of from about 35 g/l to about 55 g/l, the zinc is present in the solution in the amount of from about 30 g/l to about 50 g/l and the nitrate is present in the solution in the amount of from about 20 g/l to about 50 g/l, and wherein there is present in the solution for each part of the phosphate, from about 0.4 to about 1.2 parts of the zinc and from about 0.4 to about 1.6 parts of the nitrate;
- and wherein the total acidity of the solution is from about 110 points to about 140 points and the total acid to free acid ratio is from about 4.5 to about 8.5.
Dependencies are inferred from the claim text.