Hot corrosion phenomena of Nb-Ti-Si based alloy and its silicide coating induced by different corrosive environments at 900 °C

This study aims to elucidate the hot corrosion behavior of Nb-Ti-Si based alloy and its silicide coating in different molten salts at 900 °C. The results show that both K2SO4 and Na2SO4 had detrimental effect on the corrosion performance of the alloy, but almost no effect on the coating. However, NaCl accelerated the corrosion process for both the alloy and coating, showing highest scale thickness and mass gain. The main corrosion products consist mainly of Na or K containing oxides, TiO2 and amorphous silicate. The reactivity of the alloy and the coating in different corrosive environments is discussed.