Influence of composition and microstructure on the corrosion behavior of different Fe–Cr–Al alloys in molten LBE

Corrosion tests in molten Lead Bismuth Eutectic (LBE) are performed on materials aimed for high temperature applications. The experiments include tests with oxygen content in solution of 10−6–10−8 wt.% at temperature of 500, 600 and 750 °C for 1000 h duration. The materials under investigation are Fe–Cr–Al Kanthal like alloys, namely: Kanthal – D, AF, APM and Alkrothal. The mentioned group of alloys is discussed as alternative solution for thermally high loaded parts, e.g. spacer grids, of future accelerator driven systems (ADSs) and nuclear fast reactors cooled by molten LBE. perimental campaign highlighted the central role of temperature, oxygen content, composition (Cr and Al content) and, in some cases, microstructure for the corrosion behavior. Up to 600 °C, Kanthal alloys generally show good compatibility with LBE due to the formation of thin and protective Al2O3 scale. Even at 750 °C these alloys show the favorable alumina scale formation when the oxygen concentration in LBE is 10−6 wt.%; also at 750 °C but at lower oxygen concentration of 10−8 wt.%, dissolution attack affects Kanthal alloys except the Kanthal Alkrothal.