Static oxidation damage and life prediction of Hastelloy X alloy for aeroengine applications

Static high-temperature oxidation tests at 1000 °C for 0–500 h were performed on Hastelloy X alloy. The microstructural evolution, oxide scale and Cr-depleted zone growth kinetics, as well as mechanical properties variations were systematically characterized. An exponential decay model was established to describe tensile strength degradation under medium-to-long term oxidation. The alloy’s high-temperature service life was quantified, and the applicability and limitations of static oxidation life assessment were discussed. Oxide scales and subsurface Cr-depleted layers thickened following power-law kinetics. The alloy exhibited good microstructural thermal stability. Mechanical properties showed two-stage degradation: plasticity dropped sharply within 0–100 h, while microhardness and tensile strength slightly declined; damage saturated from 100 to 500 h. The predicted critical service life reached 1260 h. This work clarifies the degradation mechanisms of Hastelloy X under high-temperature oxidation and supports safety evaluation and maintenance optimization for aeroengine static load-bearing parts.