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 degrees 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 degrees C and above. Fe20Cr2Si exhibits the best oxidation resistance of the three in high-temperature steam.

Automated summary

FeCrSi alloys are proposed as alternatives to FeCrAl alloys for accident-tolerant fuel cladding in light water reactors and exhibit good oxidation resistance, with >= 16% Cr content being sufficient to form a passivating oxide layer. Among the three Fe-Cr-2Si alloys tested, Fe20Cr2Si showed the best oxidation resistance in high-temperature steam conditions.