Internal oxidation of Ni-Cr-Al alloys under various oxygen partial pressures at 1273 K

摘要: Alloys for high temperature application always rely on their ability to form protective, dense Cr2O3 and Al2O3 scales. In case of Ni-Cr binary alloy, a minimum composition Cr is required the formation continuous protective scale. However, addition small amount third element such as Al may results in decrease This study aims clarify effect ternary scale quantitatively. alloys composed with 2 mass% 4 were exposed oxidizing environment under Cr/Cr2O3, Fe/FeO Ni/NiO oxygen partial pressure. The oxidation all samples following parabolic rate’s law. XRD SEM show that are formed internally. Parabolic constant oxidized pressure higher by few magnitude orders. Higher concentration decreases constant. It concluded enhanced alloys.