Evolution of Oxide Phases and Residual Stress in Haynes 282 Superalloy During Long-Term High-Temperature Oxidation
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The long-term oxidation behavior of Haynes 282 superalloy was investigated in air at temperatures ranging from 800 to 950°C for durations up to 720 hours. The oxide phases formed on the alloy surface were characterized using X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS). The predominant oxide phase was identified as rhombohedral-Cr 2 O 3 , with the presence of rutile-TiO 2 , spinel-MnCr 2 O 4 , and perovskite-CoTiO 3 as secondary phases. The external oxide layer thickness increased with oxidation temperature and time, following parabolic kinetics. EDS mapping revealed the formation of an internal oxide layer, consisting of α-Al 2 O 3 and TiO 2 precipitates beneath the external Cr 2 O 3 layer. The activation energy for the long-term oxidation of Haynes 282 was calculated to be 210.05 ± 23.30 kJ mol − 1 . The residual stress in the Cr 2 O 3 layer was measured using the average X-ray strain (AXS) method. Compressive residual stresses were observed in the Cr 2 O 3 layer formed at 800°C, while tensile residual stresses were found in the layer formed at 950°C. The evolution of intrinsic stress with oxidation time and temperature was discussed in terms of the crystallite coalescence model and the Pilling-Bedworth ratio.
