C22F1/11

Chromium-molybdenum-aluminum alloys with oxidation-resistance imparted by thermal pre-treatment

Ternary chromium-molybdenum-aluminum (CrMoAl) alloys that form oxidation-resistant surface films for high-temperature applications are provided. Also provided are methods for thermally pre-treating the alloys to form the oxidation resistant surface films. The surface films have a stratified structure that includes an exterior surface oxide layer comprising chromium oxides and aluminum oxides and an interior aluminum nitride-rich region comprising aluminum nitride precipitates dispersed in a CrMoAl alloy matrix. The interior aluminum nitride precipitates act as oxygen sinks to sequester oxygen diffusing inward into the CrMoAl to prevent further oxidation of the underlying bulk alloy.