Corrosion behavior of 316 stainless steel alloy in high temperature heat storage medium containing oxygen-chloride salt

Understanding the co-adsorption of O and Cl is very important for studying the entire adsorption mechanism of 316 stainless steel (316 SS) alloy corrosion in ternary chloride salts LiCl-KCl-CaCl ₂. The influence of oxygen on the corrosion behavior of 316 SS alloy in ternary chloride salts is systematically studied through experiments combined with density functional theory (DFT) calculations. Microscopic structural and chemical experimental results indicate that oxygen in the ternary chloride salts accelerates the corrosion of 316 SS alloy. The adsorption energy and work function results indicate that as the O coverage increases, electronic transfer becomes more likely on the surface of the 316 SS alloy. Additionally, the changes in the alloy's structure and charge transfer suggest that chemical adsorption has occurred on its surface in the oxygen-containing ternary chloride salts. The charge transfer of different alloying elements increases in the order of Ni < Fe < Cr. These research findings help in understanding the corrosion mechanism of 316 SS alloy in ternary chloride salts containing impurities under air conditions.