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Due to the aforementioned effects caused by welding residual stresses, it is necessary to eliminate these stresses in some important structures that are subject to regulatory requirements or have specific performance demands. Post-weld residual stress relief can be considered in the following situations. (1) Thick-section complex structures that may be exposed to low temperatures during operation, transportation, installation, or startup, and are at risk of brittle fracture ； (2) Welded pressure vessels with a thickness exceeding a certain limit ； (3) Structures whose machining accuracy needs to be maintained after welding ； (4) Structures with high requirements for dimensional accuracy or stiffness, such as precision instruments and reducers. Because, during use, the dimensional accuracy cannot be maintained due to stress relaxation caused by structural instability, creep, or vibration. (5) Structures at risk of stress corrosion for which no effective protective measures can be taken. It has turned out that many structures can operate safely without stress-relief treatment. Whether residual stresses need to be eliminated in welded structures, and what methods should be used, must be determined through a comprehensive consideration of factors such as production experience, scientific experiments, and economic considerations. The methods for eliminating residual stresses after welding are listed in the table below. Classification of methods for removing welding residual stresses: Creep deformation method, overall annealing, local annealing, mechanical stretching method, mechanical pulling, vibration treatment, shot blasting, mechanical rolling, explosive treatment, temperature difference stretching method, low-temperature stretching, reverse welding heating treatment