Corrosion behaviour of 316 stainless steel in NaCl-KCl-MgCl2 salt vapour at 700°C

The corrosion behaviour of 316 stainless steel in NaCl-KCl-MgCl2 salt vapour at 700 °C under static conditions was investigated in this experiment. Easy-to-peel oxide layers were formed on the surface, and their composition and structure changed as exposure continued. The initially formed oxide monolayer was gradually transformed into oxide multilayers, and the outermost layer changed from Cr-Fe oxide to Mg-Cr oxide. The evolution of surface oxide layers was due to the varying diffusion rates of elements in 316 stainless steel as well as to the differing reaction rate of MgCl2 in the salt vapour.