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Material corrosion in fluoride molten salt is a core technical problem in high-temperature energy devices such as molten salt reactors, and related research has formed a relatively systematic cognitive system. The main form of core corrosion mechanism is selective dealloying. Active elements such as Cr in the alloy will preferentially react with fluoride ions to form soluble chromium fluoride, forming a loose chromium-poor layer. There are also forms of electrochemical oxidation, metallic dissolution, and mass migration corrosion caused by temperature gradients. In 2024, a new mechanism of "one-dimensional wormhole corrosion" was also discovered. Molten salt will form connected holes along the grain boundaries, greatly increasing the corrosion penetration depth. Key influencing factors: H₂O, HF and other impurities in the molten salt will significantly accelerate corrosion, and rising temperature will intensify the dissolution of Cr elements. Radiation will form defects inside the material and become a rapid diffusion channel for the corrosive medium, further worsening the corrosion effect. Typical material corrosion performance: The degree of grain boundary corrosion of iron-based alloys is about 2 times that of nickel-based alloys. Cr loss is more serious and is not suitable for this environment. ； Nickel-based alloys with low chromium and high molybdenum, such as Hastelloy N, have an annual corrosion rate of less than 0.025 mm in fluorine salts at 704°C. They are reliable materials that have been proven in long-term engineering.