Heat resistant stainless steel coated by diffusion of aluminum and the coating method thereof
AssigneesPohang Iron & Steel Co., Ltd., Research Institute of Industrial Science & Technology
InventorsByeong G. Seong, Soon Y. Hwang, Jin H. Song, Kyoo Y. Kim
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Abstract
A heat resistant stainless steel coated by diffusion of aluminum and a method of aluminum diffusion coating for heat resistant stainless steels containing nickel and chromium. The stainless steel is buried in a diffusion coating pack powder composed of an aluminum source, an activator and inert filler materials. The coating is heat treated to form a chromium-rich intermediate layer without forming an interdiffusion layer containing aluminide precipitates under an aluminide layer.
Claims16
A method of aluminum diffusion coating a heat resistant stainless steel containing nickel and chromium as main alloy components, wherein the method comprises the steps of:
- a) burying said heat resistant stainless steel in a diffusion coating pack powder composed of an aluminum source, an activator and inert filler materials,
- b) treating the steel and powder at 850.degree.-1025.degree. C. for 5-20 hours, and
- c) forming an outer aluminide layer and a chromium-rich intermediate layer on the stainless steel, without forming an interdiffusion layer containing aluminide precipitates, under the aluminide layer.
A heat resistant stainless steel coated by aluminum diffusion, wherein the coated heat resistant stainless steel comprises a chromium-rich intermediate layer formed on the stainless steel and an outer aluminide layer formed on said intermediate layer.
Dependencies are inferred from the claim text.