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Austenitic stainless steel, as the name implies, has an austenitic structure. Heat treatment is very important for austenitic stainless steel, as one of its key functions is corrosion resistance; improper heat treatment can significantly reduce its corrosion resistance. This article focuses on discussing the heat treatment of austenitic stainless steel. Austenitic stainless steel is a common type of stainless steel (18-8 steel); many kitchen utensils are made of austenitic stainless steel. Austenitic stainless steel, as the name implies, has an austenitic structure; it is non-magnetic and lacks hardenability. Austenitic stainless steel exhibits excellent corrosion resistance in oxidizing environments; an oxidizing environment can be simply understood as one with a high oxygen content. Austenitic stainless steel is tough and easy to shape, which gives it a wide range of applications. Austenitic stainless steels are primarily used for corrosion resistance, and heat treatment has a significant impact on them. The corrosion resistance and acid resistance of austenitic stainless steel depend primarily on surface passivation; if this passivation mechanism is not maintained, corrosion will occur. Therefore, austenitic stainless steel is not completely rust-proof; it is only resistant to oxidizing and acidic environments. It does not have a strong resistance to special ions. The heat treatment of austenitic stainless steel mainly affects the passivation ability of the surface layer, thereby influencing its corrosion resistance. Image: Polarization curve of 304 stainless steel, showing an anodic passivation region. Uniform corrosion is the most common type of corrosion, and it depends on the uniform distribution of chromium in the material. Heat treatment affects the distribution pattern of chromium, which in turn influences the uniform corrosion resistance of austenitic stainless steels. Intergranular corrosion is also one of the important corrosion properties used to evaluate austenitic stainless steels. Generally speaking, if austenitic stainless steel is sensitized and a large number of beaded carbides precipitate at the grain boundaries, its intergranular corrosion resistance is significantly reduced. If austenitic stainless steel is sensitized, it will suffer severe intergranular corrosion even in a very ordinary electrochemical environment. Stress corrosion cracking is the most common form of failure in austenitic stainless steels. It is important to note that stress corrosion cracking depends on two main factors: first, stress must be present, and this stress can be either applied stress or residual stress ； Secondly, there are ions sensitive to stress corrosion cracking, such as halogen ions, with chloride ions being the most common. In applications involving austenitic stainless steel, its stress-bearing capacity is not always the factor at play; therefore, special attention should be paid to residual stresses, as these can cause stress corrosion cracking in environments containing chloride ions. The method to remove residual stress is stress-relief annealing. The most terrifying corrosion. Calling it the most terrifying form of corrosion, there is no more appropriate way to describe this issue than with a saying from the ancients: \"A dike thousands of miles long can collapse because of an ant hole.\"