Patent ID: 9506136
Filing Date: 2016-11-29
CPC Classification: C23C

Claim Text:
1. A method of coating an iron-based article, the method comprising: in a first heating step, heating a substrate including an iron-based material in the presence of an aluminum source material and a halide diffusion activator, in a substantially non-oxidizing environment, to cause formation of an aluminum-rich layer on at least a portion of the iron-based material; and in a second heating step, heating the substrate that has the aluminum-rich layer in an oxidizing environment to oxidize the aluminum in the aluminum-rich layer, wherein the first heating step includes heating at a heating temperature such that a ratio of the melting temperature of the iron-based material to the heating temperature is 1.5-2.1 and, after the second heating step, cooling the substrate at a rate of equal to or less than 10° C. per minute, and wherein the iron-based material is stainless steel.