Effect of Temperature and Impurity Content to Control Corrosion of 316 Stainless Steel in Molten KCl-MgCl2 Salt

作者：Na Li, Huaiyou Wang, Huiqin Yin, Qi Liu, Zhongfeng Tang · 发表于：Materials · 年份：2023 · DOI：10.3390/ma16052025 · 被引用次数：19 · 研究领域：Phase Change Materials Research、Advanced ceramic materials synthesis、Molten salt chemistry and electrochemical processes

The corrosion resistance of 316 stainless steel (316SS) in molten KCl-MgCl2 salts was studied through static immersion corrosion at high temperatures. Below 600 °C, the corrosion rate of 316SS increased slowly with increasing temperature. When the salt temperature rises to 700 °C, the corrosion rate of 316SS increases dramatically. The corrosion of 316SS is mainly due to the selective dissolution of Cr and Fe at high temperatures. The impurities in molten KCl-MgCl2 salts could accelerate the dissolution of Cr and Fe atoms in the grain boundary of 316SS, and purification treatment can reduce the corrosivity of KCl-MgCl2 salts. Under the experimental conditions, the diffusion rate of Cr/Fe in 316SS changed more with temperature than the reaction rate of salt impurities with Cr/Fe.