Method for deposition of steel protective coating
First Claim
1. A coated steel article, comprising:
- a workpiece having a steel surface;
a hydrogen barrier coating comprising a thickness not greater than about 2.54 microns on the steel surface;
a zinc-nickel alloy layer on the hydrogen barrier coating, the zinc-nickel alloy layer comprising about 85 weight percent to about 95 weight percent zinc and about 5 weight percent to about 15 weight percent nickel; and
a conversion coat sealing the zinc-nickel alloy layer,wherein said hydrogen barrier coating is a previously activated hydrogen barrier coating, andwherein the conversion coat is comprised of zinc phosphate, which forms a first coating layer, and trivalent chromate, which forms a second layer, where the first coating layer coats said zinc-nickel alloy layer.
1 Assignment
0 Petitions
Accused Products
Abstract
A method is provided for coating a steel surface of a workpiece. According to an aspect of the invention, a steel workpiece is subjected to a first embrittlement-relief baking operation to form a protective oxide layer on the steel surface. The protective oxide layer is de-scaled, and the steel surface is activated. A hydrogen barrier coating is deposited on the activated steel surface, and activated. A zinc-nickel alloy is plated on the barrier coating, and subjected to a second embrittlement-relief baking operation. The porous plating is sealed with a conversion coat. The method is especially useful in making low to no hydrogen embrittlement cadmium-replacement steel parts. Also provided is a corrosion resistant coated steel workpiece.
-
Citations
6 Claims
-
1. A coated steel article, comprising:
-
a workpiece having a steel surface; a hydrogen barrier coating comprising a thickness not greater than about 2.54 microns on the steel surface; a zinc-nickel alloy layer on the hydrogen barrier coating, the zinc-nickel alloy layer comprising about 85 weight percent to about 95 weight percent zinc and about 5 weight percent to about 15 weight percent nickel; and a conversion coat sealing the zinc-nickel alloy layer, wherein said hydrogen barrier coating is a previously activated hydrogen barrier coating, and wherein the conversion coat is comprised of zinc phosphate, which forms a first coating layer, and trivalent chromate, which forms a second layer, where the first coating layer coats said zinc-nickel alloy layer. - View Dependent Claims (2, 3, 4, 5, 6)
-
Specification