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Considering the previous application context of water-cooled reactor systems, there is a clear performance gradient in terms of the stability of high-temperature oxide films for different materials, as follows: First, FeCrAl alloy – its key advantage lies in its ability to form a dense Al₂O₃ protective film at high temperatures; this film can effectively prevent oxygen diffusion even in a steam environment at 1200°C, granting it excellent resistance under accident conditions. Performance: It is currently the key candidate material for fuel cladding with accident tolerance in water-cooled reactors, offering significantly superior high-temperature oxidation resistance compared to traditional zirconium alloys. II. Austenitic stainless steel: Key advantage – it forms a continuous Cr₂O₃ passivation layer at high temperatures; this layer bonds tightly to the matrix, enabling rapid self-repair after minor damage. Performance: It can operate stably for long periods in water environments at temperatures below 500°C, with an extremely low risk of oxidation film aging or peeling; it is thus the dominant structural material used inside reactors. III. Zirconium alloys: Key advantage – excellent self-healing property of the oxide film under normal operating conditions; they are the cladding materials widely used in traditional pressurized water reactors. Performance weaknesses: The corrosion rate increases significantly when the temperature exceeds 400°C; at high temperatures of 1200°C, it undergoes a vigorous zirconium-water reaction with water vapor, causing the oxide layer to fail rapidly. IV. Carbon steel: Its main weakness is that the oxide film it forms is loose and porous, with weak adhesion to the base material; it cracks and peels off easily at high temperatures, making it unsuitable for use in environments subject to high-temperature corrosion over extended periods of time. Overall, the stability of the oxide film at high temperatures, from highest to lowest, is as follows: FeCrAl alloy > austenitic stainless steel > zinc alloy > carbon steel, with the FeCrAl alloy showing the most outstanding stability of its oxide film at high temperatures.