Method for applying chromium-containing coating to metal substrate and coated article thereof

摘要

A method for applying a chromium containing coating (46, 58) to an underlying metal substrate (21) where the metal substrate (21) has an overlaying platinum-containing layer (50), as well as a corrosion resistant coated article (20) thereof. A chromium-containing layer (58) is deposited on the platinum-containing layer (50) with an aluminide diffusion layer (66) being deposited on the chromium-containing layer (58), the aluminide diffusion layer (66) having an inner diffusion layer (72) adjacent the chromium-containing layer (58) and an outer additive layer (78) adjacent to the inner diffusion layer (78). The chromium-containing layer (58) is deposited by a deposition technique that permits chromium in the chromium-containing layer (58) to more readily diffuse into a subsequently deposited aluminde diffusion layer (66). The chromium-containing and aluminide diffusion layers (58, 66) are then treated to cause chromium from the chromium-containing layer (58) to diffuse into the outer additive layer (78) in an amount of at least 8%. The resulting coated article (20) is resistant to corrosion.