The corrosion behavior of 316 stainless steel (SS) was studied in the natural circulation of eutectic molten NaCl-MgCl2 salt using the microloop concept. The post-corrosion tested 316 SS microloop sections were characterized with microscopy techniques to understand the microstructural and microchemical changes that occurred at the alloy/salt interface. It was found that 316 SS showed heterogeneous dissolution at the hot-leg, whereas the deposition of corrosion products occurred at the cold-leg. For the first time, the experimentally obtained molten salt flow-induced corrosion of 316 SS results were combined with computational methods using thermodynamic-kinetic modeling to validate the dissolution and deposition in terms of elemental compositional changes at the alloy/salt interface. The agreement between modeling and experimental results confirms that Fe chlorides dissolve at the hot-leg and subsequently deposit at the cold-leg due to activity changes driven by the thermal gradient. In contrast, Cr was not detected in the cold-leg deposits, which is attributed to its weaker temperature dependence in activity, limiting its redeposition under these conditions.
