High Temperature Oxidation of the Haynes 282© Nickel-Based Superalloy

Nickel-based superalloys are used in applications where corrosion and oxidation resistance at high temperatures are required together with microstructural stability. Superalloys with different metallurgical characteristics are therefore currently being developed; the high temperature behaviour of these systems must be evaluated. In this investigation, the isothermal oxidation resistance of a Haynes 282(A (c)) nickel-based superalloy was studied by gravimetric means in the temperature range 800-1,000 A degrees C for relatively short exposure times up to 150 h. The results from the tests suggest that the parabolic rate law describes the oxidation kinetics of the alloy. The chemical composition of the oxides present in the scale comprised an outer TiO2 layer and an inner Cr2O3 layer, with the latter located at the metal/oxide interface(.) In addition, the formation of an internal oxidation zone of Al2O3 and TiO2 was also observed at all temperatures. The role of oxide formation on microstructural changes experienced by the alloy is discussed.