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

Na Li; Huaiyou Wang; Huiqin Yin; Qi Liu; Zhongfeng Tang

doi:10.3390/ma16052025

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

Materials (Basel). 2023 Feb 28;16(5):2025. doi: 10.3390/ma16052025.

Authors

Na Li^{1

2}, Huaiyou Wang³, Huiqin Yin¹, Qi Liu¹, Zhongfeng Tang^{1

2

4}

Affiliations

¹ Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China.
² University of Chinese Academy of Sciences, Beijing 100049, China.
³ Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, China.
⁴ Dalian National Laboratory for Clean Energy, Dalian 116023, China.

Abstract

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.

Keywords: KCl-MgCl2; alloy; corrosion; high temperature; molten salt.

Abstract

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