Patent ID: 6537388
Filing Date: 2003-03-25
Classification: C10G,C23C,Y02T

Abstract:
A method of coating a surface of a metal product formed from a metal alloy selected from the group consisting of iron based alloys, nickel based alloys and nickel base alloys containing chromium, comprising:preparing the surface to remove diffusion limiting oxides; and diffusing a sufficient amount of chromium and silicon into the surface to form a first coating having a thickness of at least 0.0005 inch (0.0127 millimeters), containing at least 8 weight percent more chromium than contained in the substrate alloy, which is followed by diffusing a sufficient amount of aluminum, or aluminum-silicon to form on the first coating a second coating having a total thickness of at least 0.005 inch (0.0127 millimeters) and containing at least 20 weight percent aluminum at the coating surface.