摘要
The long-term oxidation behavior of the HAYNES (R) 282 (R) superalloy was systematically investigated in air at temperatures ranging from 800 to 950 degrees C for durations of up to 720 h. The oxide phases that developed on the surface of the alloy were characterized using X-ray diffraction and energy-dispersive X-ray spectroscopy (EDS). The residual stress within the Cr2O3 layer was assessed utilizing the average X-ray strain method. The primary oxide phase was identified as rhombohedral Cr2O3, with secondary phases including rutile-TiO2, spinel-MnCr2O4, and perovskite CoTiO3. The thickness of the external oxide layer increased with both oxidation temperature and time, adhering to parabolic kinetics. EDS mapping indicated the dispersion of Al-rich and Ti-rich oxides internally, suggesting the precipitation of Al2O3 and TiO2 beneath the external Cr2O3 layer. The activation energy for the long-term oxidation of HAYNES (R) 282 (R) was calculated to be 272.5 +/- 15.0 kJ mol(-1). The total residual stresses within the Cr2O3 phase measured at room temperature were found to be entirely compressive. The calculated intrinsic residual stress associated with Cr2O3 growth at 800 degrees C exhibited a transition from tensile to compressive, whereas at 950 degrees C, it remained tensile. The evolution of intrinsic stress in relation to oxidation time, temperature, and scale thickness was discussed in the context of the crystallite coalescence model and the Pilling-Bedworth ratio.