Patent ID: 7875200

Claim:
A method for a repair process, comprising: (a) subjecting a substrate coated with at least one protective metallic coating to a nitric acid solution having a molarity of 0.07M-0.80M at a first temperature of about 60° F.-160° F., the substrate being comprised of about 5 wt %-15 wt % chromium, about 2 wt %-8 wt % cobalt, about 2 wt %-6 wt % tungsten, about 0.5 wt %-2.5 wt % titanium, about 8 wt %-16 wt % tantalum, about 2 wt %-8 wt % aluminum, hafnium in an amount no greater than 1 wt %, and a remainder of nickel; and (b) after said step (a), subjecting the substrate coated with the at least one protective metallic coating to a hydrochloric acid solution having a molarity of 0.65M-0.85M at a second temperature of about 120° F.-180° F. to remove the at least one protective metallic coating from the substrate and limit etching of hafnium carbide in the substrate.