Method for reducing residual stress of metal structure material fusion welding joint

Abstract

The invention provides a method for reducing residual stress of a metal structure material fusion welding joint. According to the method, heated gas and high-speed particle flows are utilized to simultaneously impact a weld joint area and the part near the weld joint area, the pressure stress is generated on the surface of the joint, so that the stress distribution is improved, the fatigue strength of the joint is improved, and the service life of the joint is prolonged; the size of the impact particles mostly ranges between 10 microns and 100 microns, the acceleration of the particles can berealized through high-pressure compressed gas (helium, nitrogen or compressed air), the gas pressure generally ranges from 1.5 MPa to 3.5 MPa, and the particle speed can reach the speed ranging from 400 m / s to 1000 m / s; in addition, the gas can be preheated according to requirements, and the preheating temperature generally ranges from 200 DEG C to 600 DEG C; in the method, the high-speed particleimpact effect and the hot gas impact effect are combined so that the residual tension of a component can be effectively reduced or eliminated, the mechanical property of the joint can be improved, and the service life of the component can be prolonged; and the method can be used for regulating and controlling the residual stress of the metal structure material fusion welding joint, and can also be used for improving the residual stress distribution of various welding joints of other materials, so that the safety and reliability of the joint are improved.

Description

technical field [0001] The invention belongs to the technical field of connection of metal structural materials, and in particular relates to a method for reducing the residual stress of welded joints of metal structural materials. Background technique [0002] Many industrial fields such as aerospace, petrochemical, automobile and ship, pressure vessel, etc. will involve the connection technology of metal structural materials. During welding, the weld area is heated and expanded locally, and cannot be freely elongated due to the constraints of the part far away from the weld, so that the weld area is compressed to produce plastic deformation; The constraints in the far part of the weld zone cannot be shortened freely, so residual tensile stress is generated after welding. The existence of residual tensile stress will not only reduce the bearing capacity of components, but also significantly affect the accuracy and dimensional stability of components. At the same time, resi...

AI Technical Summary

Problems solved by technology

This method is low in cost and easy to operate, but it will increase the surface roughness of the workpiece, deteriorate the corrosion resistance, and the working environment is harsh, and the unit output is low

[0008] (5) The patent application number 200910024032.4 discloses a method for reducing the residual stress of ferromagnetic metal materials. The ferromagnetic metal materials are treated by pulse current and pulse magnetic field to achieve the effect of reducing residual stress, but this method is only applicable to ferromagnetic materials. Materials, for non-ferromagnetic materials, the purpose of reducing residual stress cannot be achieved

However, this method is only applicable to TIG welded joints, and the stress distribution of other solid phase welded joints cannot be controlled

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