Experiments and cellular automata simulation of corrosion and protection of Hastelloy X in high-temperature chloride molten salts

Molten salts are excellent heat transfer and storage materials due to their outstanding properties, but their strong corrosive properties at high temperatures will cause severe negative consequences. In this paper, a cellular automata (CA) model is developed by MATLAB software to simulate the corrosion behavior of Hastelloy X alloy in NaCl–KCl–MgCl2 ternary molten salt. The simulated reliability is validated through a 7-day corrosion experiment. The simulation investigated factors influencing corrosion layer thickness, studied the formation of pitting behavior, and simulated the corrosion inhibition of surface coatings. The simulation results indicated that the composition of alloy, the concentration of O2 and Cl2, and the reaction rate are the main reasons for the serious corrosion of the alloy. By increasing the density and thickness of the coating can effectively alleviate corrosion. Compared with conventional corrosion experiments, the CA model can monitor real-time atomic migration at the metal-molten salt interface, track element distribution within the metal, and shorten the corrosion experiment period, which is of significance to study and predict the corrosion behavior of alloys in molten salts.