Focus point control laser welding method

Abstract

The invention discloses a focus point control laser welding method. In the welding process, focus points of laser beams are vertically vibrated while the focus points transversely swing relative to awelding workpiece, the vibration frequency is 100-500 Hz, the amplitude is 0.3 time smaller than the thickness of the welding workpiece, the swing frequency is 10-500 Hz, and the swing amplitude is 0-1.5 mm. By means of the focus point control laser welding method, since the laser welding method of vertically vibrating the focus points while transversely swinging the focus points in the welding process is adopted, by adjusting the amplitudes and frequencies of vertical vibration and transverse swing, the purposes that the workpiece dimension tolerance of the workpiece is compensated, the butt-joint interstice tolerance is improved, and the fusion depth of welding joints is increased are effectively achieved, and the power needed in the welding process is lowered.

Description

technical field [0001] The invention relates to a laser welding method for metal material workpieces, in particular to a focus control laser welding method applicable to the fields of welding longitudinally welded pipelines, railway passenger cars, sea ships and the like. Background technique [0002] Laser welding has outstanding advantages such as high energy density, fast welding speed, large weld depth-to-width ratio, good joint performance, and small deformation of the welded structure. With the development of industrial lasers, especially the application of high-power fiber lasers, laser welding technology has also been more and more widely used. However, laser welding requires extremely high assembly accuracy of the workpiece. When the assembly accuracy is not up to the requirement, resulting in too large gap between the workpieces, the laser will directly pass through the gap, resulting in poor welding defects. At present, the main methods are to increase the spot di...

AI Technical Summary

Problems solved by technology

However, laser welding requires extremely high assembly accuracy of the workpiece. When the assembly accuracy is not up to the requirement, resulting in too large gap between the workpieces, the laser will directly pass through the gap, resulting in poor welding defects. At present, the main methods are to increase the spot diameter or The double-beam method is used to solve this problem. However, increasing the spot diameter to achieve the same penetration requires increasing the corresponding laser power, resulting in high equipment costs. Double-beam laser welding can improve the stability of the laser welding process and reduce welding porosity, but the laser Reduced energy density reduces its weld penetration

Studies have shown that beam swing can also be used to improve the tolerance of workpiece gaps. Swing welding can stir the molten pool, which is conducive to the escape of bubbles in the molten pool, so the pores in the weld are reduced, but compared with double-beam laser welding Similarly, the weld penetration obtained by beam rotation or oscillating laser welding methods is also significantly reduced

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