Corrosion behavior of 310S stainless steel in molten KCl–AlCl3–ZrCl4 salt at 350°C

This work investigates the corrosion behavior of 310S stainless steel in KCl–AlCl 3 –ZrCl 4 (25-45-30 wt%) molten salt at 350°C for potential application in zirconium(Zr)-hafnium(Hf) distillation reactors. The results indicate that corrosion is mainly governed by impurity-driven reactions involving H 2 O and O 2 , which generate HCl and Cl 2 and induce the selective dissolution of Fe and Cr. After 100 h immersion, a bilayer corrosion product structure is formed, consisting of a compact inner oxide layer and an outer porous salt-oxide layer. Optimizing the film formation potential promotes enrichment of NiO in the passive film, which shifts the corrosion rate-controlling step from diffusion control to charge-transfer control. These results indicate that 310S stainless steel exhibits promising compatibility with KCl–AlCl 3 –ZrCl 4 molten salt under the present experimental conditions and provide a reference for material selection in molten salt distillation reactors.