Effect of water vapor on the oxide growth in FeCrAl-based oxide dispersion-strengthened fuel cladding material at 1100 ℃ and 1200 ℃

As a potential accident-tolerant fuel cladding material, the high-temperature oxidation behavior of Fe-13Cr-4.5Al-oxide dispersion-strengthened alloy was investigated in dry air and moist air at 1100–1200 ℃. The specimens were examined using a combination of gravimetry and several surface-analytical techniques, including X-ray diffraction, scanning electron microscopy, electron probe microanalysis, focused ion beam, and transmission electron microscopy. The oxidation occurred rapidly at first and then slowed down as the protective oxide layer developed. A typical two-layer alumina grain structure was observed in both environments. An oxide growth mechanism of the Fe-13Cr-4.5Al-ODS alloy is proposed, emphasizing the effect of water vapor.