Effect of Y{sub}2O{sub}3 content on the oxidation behavior of Fe-Cr-Al-based ODS alloys

摘要

A study was conducted to investigate the cyclic oxidation behavior of two oxide dispersion strengthened (ODS) Fe-Cr-Al based alloys containing 0.17 wt. % and 0.7 wt. % Y{sub}2O{sub}3. The alloys were oxidized in air for 100 h at 1200℃ based on a 24 h cycle period. X-ray diffraction (XRD) and analytical transmission electron microscopy (TEM) were used to characterize the structure, morphology, and composition of the oxide scales. Both alloys formed highly adherent and continuous layers of α-Al{sub}2O{sub}3 exhibiting a morphology indicative of inward scale growth. The role of Y{sub}2O{sub}3 was to promote adherence by segregating to the grain boundaries within the oxide. Concurrently, Y{sub}2O{sub}3 generated micro-porosity resulting in a scale of comparatively higher thickness in the alloy with 0.7 wt.% Y{sub}2O{sub}3.