Effect of Y_2O_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. percent and 0.7 wt. percent Y_2O_3. the alloys were oxidized in air for 100 h at 1200 deg C based on a 24 h cycle period. X-ray diffraction (XRD) and analytical transmission electro microscopy (TEM) were used to characterize the structure, morphology, and composition of the oxide scales. Both alloys formed highly adherent and continuous layers of alpha-Al_2O_3 exhibiting a morphology indicative of inward scale growth. The role of Y_2O_3 was to promote adherence by segregating to the grain boundaries within the oxide, Concurrently, Y_2O_3 generated micro-porosity resulting in a scale of comparatively higher thickness in the alloy with 0.7 wt. percent Y_2O_3.