Laser welding method combining ultrasonic welding with chilling

Abstract

The invention belongs to the field of welding, and relates to a laser welding method combining ultrasonic welding with chilling. According to the method, cooling water is applied to the back surface of a welding seam with a certain distance behind a molten pool in the welding process, and ultrasonic vibration is applied to the front surface; the temperature and the flow of the cooling water are determined according to the welding mode used; and the ultrasonic application position, power and force are adjusted according to the mechanical properties of sample materials. According to the method,the welding residual stress can be effectively reduced, and air holes and cracks are reduced, so that the fatigue performance of the welding seam is improved, and meanwhile, transverse and longitudinal deformation of welding is reduced. Longitudinal residual stress and deformation can be effectively reduced through chilling and welding. The ultrasonic impact can counteract the transverse stress caused by chilling and welding, and further inhibit longitudinal stress, so that deformation is effectively reduced; and the acoustic streaming effect and cavitation effect of the ultrasonic can refinecrystal grains and reduce the air holes and cracks, so that the fatigue performance of the welding seam is improved.

Description

technical field [0001] The invention belongs to the field of welding and relates to a laser welding method combined with welding ultrasonic and chilling. Background technique [0002] Welding is a heating and cooling process with localized heating and cooling. When heated, the metal around the weld expands, producing compressive plastic deformation under the restraint of the fixture. When cooling, this part of the metal shrinks to produce tensile plastic deformation, elastic deformation and tensile stress. The stress that still exists after cooling to room temperature is the residual stress. When the clamp is released after welding, the residual stress is redistributed, and the workpiece is deformed under the action of the stress. It can be seen that the main cause of welding deformation is welding residual stress. [0003] The workpiece will produce residual stress after welding, which will cause welding deformation and reduce the fatigue performance of the weld. Theref...

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Problems solved by technology

However, the adverse effect of this method on lateral shrinkage deformation has not been completely eliminated by clamp restraint

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