Patent ID: 7744813

Claim:
An austenitic stainless steel HTUPS alloy, comprising in weight percent: 15 to 21 Ni; 10 to 15 Cr; 2 to 3.5 Al; 0.5 to 4 Mn; 1 to 3 Mo; 0.1 to 1 Si; 0.1 to 1 Nb; 0.05 to 0.15 C; less than 0.05 N; less than 0.3 of combined Ti+V; and base Fe, where the weight percent Fe is greater than the weight percent Ni wherein said alloy forms an external continuous scale comprising alumina, nanometer scale sized NbC comprising particles distributed throughout the microstructure, and a stable essentially single phase fcc austenitic matrix microstructure.