Method for evaluating welding residual stress

Abstract

The invention discloses a method for evaluating welding residual stress. The method comprises the following steps of: collecting a magnetic signal of a welding joint, collecting magnetic signals of atest material under different stresses through a static load tensile test, achieving longitudinal / transverse separation of the magnetic signals by combining correlation analysis between longitudinal residual stress and transverse residual stress of the welding joint, further extracting magnetic signal characteristic parameters capable of representing welding longitudinal stress, and finally, realizing the effective evaluation of the longitudinal residual stress of the welding joint by establishing the corresponding relationship between the stress and the magnetic signal characteristic parameters. According to the method, by establishing the corresponding relation between the stress and the magnetic signal characteristic parameters, quantitative evaluation of the stress value and the direction of a welding sample can be achieved, and meanwhile the method has the advantages of being free of damage, rapid, safe, capable of achieving online operation and the like.

Description

technical field [0001] The invention relates to a method for evaluating residual stress, in particular to a method for evaluating welding residual stress. Background technique [0002] Residual stress is one of the important factors that affect or even determine the service safety of welded structures. Therefore, it is extremely important to explore methods that can realize the evaluation of welding residual stress to ensure the service safety and quality of welded structures and their equipment. At present, residual stress evaluation methods can be divided into two categories: non-destructive methods and destructive methods. The destructive method is a kind of method to realize the stress evaluation on the basis of destroying the welded structure or the overall performance of the equipment, such as the small hole method. Although this type of method can realize the stress evaluation, it has the following problems: ① It cannot be realized on-site, quickly , Online applicati...

AI Technical Summary

Problems solved by technology

The destructive method is a kind of method to realize the stress evaluation on the basis of destroying the welded structure or the overall performance of the equipment, such as the small hole method. Although this type of method can realize the stress evaluation, it has the following problems: ① It cannot be realized on-site, quickly , online application; ②The evaluation result is the result of a small sample random check

However, in the existing methods, the metal magnetic memory signal is mainly evaluated with uniform / unidirectional stress, which cannot be applied to the complex characteristics of welding residual stress.

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