Method and system for lowering laser welding residual stress by coupling high-energy pulse current

Abstract

The invention discloses a method for lowering laser welding residual stress by coupling high-energy pulse current. The method is characterized in that laser spots are concentrated at a weld joint of aworkpiece, and laser welding is carried out on the workpiece; the high-energy pulse current acts on a weld joint molten bath at the same time of laser welding of the workpiece; after laser welding iscompleted and when the temperature of the weld joint is lowered to 100 DEG C or below, the high-energy pulse current stops acting; and the high-energy pulse current is damped oscillating high-energypulse current. A system for lowering the laser welding residual stress by coupling the high-energy pulse current is characterized by comprising a pulse laser source, a pulse laser control unit, a working platform, an insulation bottom plate, a movement control main machine, a high-energy pulse power source, a copper electrode 1 and a copper electrode 2. The method and system have the advantage ofbeing capable of conducting high-energy pulse current and laser welding coupling treatment on metal materials in a solidification and crystallization process and metal solid materials, thereby lowering the laser welding residual stress from the source causing defects.

Description

technical field [0001] The invention relates to the field of welding technology, in particular to a method and system for reducing laser welding residual stress by coupling high-energy pulse current. technical background [0002] Laser welding is an important material forming process, which is widely used in aerospace, marine engineering, automobile and other fields. However, laser welding is a process of rapid heating and cooling of a local area of ​​the material. The non-uniform temperature field will generate residual stress in the formed material, especially the large tensile residual stress in the weld area, thereby reducing the The yield strength and fatigue life of materials increase the effect of stress corrosion cracking, and are also important reasons for material deformation and crack initiation, expansion, and cracking. Therefore, how to eliminate the tensile residual stress generated during laser welding of materials has always been an important research topic ...

AI Technical Summary

Problems solved by technology

[0007] To sum up, it is not difficult to find that the above-mentioned residual stress relief process can eliminate the residual stress of metal materials after welding to a certain extent. Coarse microstructure defects are produced during solidification and crystallization, and these defects are difficult to eliminate by residual stress relief process

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