Abstract There is provided a surfaced alloyed metal product and a method for production thereof. The metal part to be surface alloyed is coated with a decomposable compound, coated with an alloying material, and heated to an elevated temperature above the decomposition temperature of the decomposable compound in a dry gaseous atmosphere, especially in a hydrogen atmosphere. The decomposable compound must contain at least one element which has an atomic volume greater than the atomic volumes of the elements of the metal part to be surface alloyed and the alloying materials. Preferably the decomposable compound contains an element which has an atomic volume at least 1.1 times the atomic volumes of the metal part and alloying material.
The process according to claim 1 wherein the said coating of alloying metal is applied in an aqueous solution containing a member selected from the group consisting of organic borates and silicates and inorganic borates and silicates.
Claim 3
Dependent Claim
13 words
A process according to claim 1 wherein the said decomposable compound contains Mn.
Claim 4
Dependent Claim
20 words
applying a second coating of an aqueous solution of at least one reduceable salt or oxide of an alloying metal,
Claim 5
Dependent Claim
4 words
drying said second coating,
Claim 6
Dependent Claim
13 words
A process according to claim 1 wherein the said decomposable compound contains Mo.
Claim 7
Dependent Claim
19 words
The process according to claim 1 wherein the said coating of alloying metal comprises Chromium, Aluminum, Yttrium and IRon.
Claim 8
Dependent Claim
95 words
subjecting the so-coated substrate in a dry, gaseous atmosphere to an elevated temperature sufficient to decompose said decomposable compound and thereby forming a barrier layer of said at least one large element of the said decomposable compound and to reduce said reduceable salt or oxide to an alloying metal capable of alloying with said metal substrate thereby forming a surface alloy coating, and whereby said large element of said barrier layer is disposed on or partially in the surface of said metal substrate and said alloying metal is disposed on and through said barrier layer.