Influence of alkaline earth metal CaCl2 on early-stage corrosion behavior of 316 stainless steel in high-temperature molten salt

Ternary chloride salts containing alkaline earth metal salts are potential high-temperature thermal energy storage (TES) media for future applications. However, the effect of alkaline earth metal salts on the corrosion of 316 stainless steel (SS) is still not well understood. In this paper, the short-term corrosion behavior of two ternary chloride salts, LiCl-KCl-CaCl2, with different CaCl2 contents on 316 SS at 650 degrees C was studied through a combination of experiments and first-principles molecular dynamics simulations. The effect of impurity water introduced by CaCl2 on the formation and evolution of corrosion products was revealed by experimental methods. The dynamic interaction between impurity water introduced by the chloride salts and the salt mixture LiCl-KCl-CaCl2 with different components was studied by molecular dynamics simulations. The experimental and simulation results show that the impurity water introduced by CaCl2 promotes the corrosion of 316 SS. These findings provide new insights for molten salt design and corrosion control of high-temperature TES for concentrated solar power.