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The selection of corrosion-resistant alloys for water-cooled reactor systems needs to be based on the working conditions of different components, giving priority to the corrosion resistance, mechanical properties and radiation stability of the materials. The core selection directions are as follows: 1. Inconel 690 (0Cr30Ni60Fe10) nickel-based alloy is mainly used for heat transfer tubes in steam generators. Its chromium content reaches 27%~31%, which can form a dense Cr₂O₃ passivation film. Its resistance to intergranular corrosion and stress corrosion cracking is much better than that of the early 600 alloy. It is suitable for high-temperature and high-pressure water environments in primary circuits. Currently, the domestic application of this material has been realized in China. 2. Structural parts within the reactor are selected with austenitic stainless steel as the core: Second-generation reactors commonly use 304L, 304LN, 321 and other brands, and 316LN and 321H are used for bolts. ； The third-generation AP1000 stack model uses forged F304 and F304H stainless steel, which have low neutron absorption cross-sections and excellent corrosion resistance and processing and welding properties. 3. Zirconium alloy is used as the fuel cladding material for conventional pressurized water reactors. Typical grades include Zr-4 and domestic N36 zirconium alloy. Its thermal neutron absorption cross-section is extremely low, and its corrosion resistance and mechanical properties are excellent in 300~400°C operating conditions. ； However, zirconium alloy is no longer suitable under supercritical water-cooled reactor conditions. Nickel-based 625, Incoloy-800H and other alloys can be used. The corrosion resistance ranking under 500℃/25MPa environment is:: Alloy 625 > Alloy 800 > 316 SS > 304 SS.