Dry and Wet Air Oxidation Study of Next Generation Chromia-Forming Heat Resistant Alloy

This study investigates the chromia-forming Ni-based heat-resistant alloy UCX. The initial analysis of the as-cast microstructure, primarily comprising eutectic carbide and an austenitic matrix, also reveals various secondary phases and inclusions. Preliminary findings suggest that during an 8-h ramp-up from ambient temperature to 950 °C in flowing argon, the eutectic carbide dissolves and re-precipitates as needle-like secondary carbide. The thickness and morphology of oxides vary depending on whether they form above the previous eutectic carbide phase or the previous austenitic phase.