Corrosion behaviour of stainless steels and a single crystal superalloy in a ternary LiCl-KCl-CsCl molten salt

In the present work, the corrosion properties of a low-carbon stainless steel (X2CrNi18-9) and a Ti-stabilised high-carbon stainless steel (X6CrNiTi18-10) were investigated in a molten LiCl-KCl-CsCl salt at 400, 500, and 600 °C for 1, 3, 9 and 27 h. In addition, a Ni-based superalloy (CMSX-4) was tested at 800 °C for 3 h. The low-carbon steel revealed severe intergranular corrosion for all testing conditions, whereas the Ti-stabilised steel was protected against intergranular corrosion by a Cr2O3 passive layer for short exposure times and up to a temperature of approximately 500 °C. In comparison, CMSX-4 revealed superior corrosion resistance.