Welded tube for strengthening welded joint by laser shock

Abstract

The invention relates to a welded tube for strengthening a welded joint by laser shock. The welded tube is prepared from the following processing steps of: irradiating by a pulse laser of which the power is 0.4-0.6kW on the surface of the welded joint of the welded tube, and generating explosive gases at the surface layer of the welded joint to form an impact wave, wherein a microstructure of the surface layer of the welded joint is stressed to plastically deform; the internal dislocation density of the welded tube is increased, and a strengthening layer is formed, so as to form the welded tube. The interior porosity of the welded tube disclosed by the invention is reduced; the organization is thinned; the grain boundary is increased, and the mechanical property is improved.

Description

technical field [0001] The invention relates to a welded pipe that uses laser shock to strengthen the welded joint, in particular to an X70 pipeline steel welded pipe that uses laser shock to strengthen the welded joint. Background technique [0002] The X70 pipeline steel welded pipe is formed from a plate to a pipe by submerged arc automatic welding. The welded joint has a large residual stress and structural inhomogeneity, generally only 50% to 60% of the strength of the base material. weakness. Due to the input of a large number of heat sources during the welding process, welding residual tensile stress is prone to occur, resulting in salt spray corrosion, resulting in failure of stress corrosion cracking of welded joints. Therefore, it is necessary to carry out surface anti-corrosion treatment for pipeline steel welded joints. [0003] At present, shot peening is mainly used to introduce residual compressive stress to improve the salt spray corrosion resistance of wel...

AI Technical Summary

Problems solved by technology

[0004] (1) The consistency of shot peening coverage cannot be guaranteed;

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