Oxidation behavior of Fe-Cr-2Si alloys in high temperature steam

FeCrSi alloys have been proposed as alternatives to FeCrAl alloys for accident-tolerant fuel cladding in light water reactors. Experiments on the oxidation resistance of three Fe-Cr-2Si alloys in high-temperature steam, with 12, 16, and 20 wt. % Cr, show that ≥16 % Cr is sufficient to form a thin, passivating, binary oxide layer. At 1200 °C, only Cr2O3 and SiO2 form on Fe16Cr2Si and Fe20Cr2Si, while additional ternary Fe oxides form on Fe12Cr2Si. Decohesion and spalling of oxide were observed on Fe-Cr-Si alloys exposed to steam at 900 °C and above. Fe20Cr2Si exhibits the best oxidation resistance of the three in high-temperature steam.