Scanning laser-TIG electric arc composite penetration fusion welding method

Abstract

The invention relates to a scanning laser-TIG electric arc composite penetration fusion welding method. The method comprises the steps that a laser beam and TIG electric arc both act on a workpiece, awelding pool is formed, the laser beam is vertically downwards arranged, and the TIG electric arc is arranged on the rear side of the laser beam and is oblique by a certain angle. During composite welding, the front end of the welding pool of the workpiece is filled with a welding wire, by adjusting the scanning track, the scanning frequency and the scanning range of the laser beam, the scanningpath of a focal spot of the laser beam is oval or round in the workpiece thickness direction, a weld joint is formed, and workpiece welding is completed. By means of the method, small hole stability is facilitated, the welding quality is easily improved, then the back bead width and weld joint back width ratio of the penetration fusion weld joint is improved, and the mechanical properties of a joint are further improved.

Description

technical field [0001] The invention relates to the field of welding technology, in particular to a scanning laser-TIG arc composite deep penetration welding method. Background technique [0002] Laser arc hybrid welding combines two heat sources with completely different physical properties and energy transmission mechanisms, and acts on the same processing position at the same time. It can not only give full play to the respective advantages of the two heat sources, but also make up for their respective deficiencies. A new and efficient welding method has been developed. Among them, the laser-TIG arc hybrid welding process is stable (TIG welding is tungsten inert gas welding, generally called non-melting electrode gas shielded welding), the arc stability is good, and it is easy to obtain a good weld shape. [0003] In the laser arc hybrid welding process, the laser heat source plays a major role in the weld penetration, and the arc heat source plays a major role in the we...

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Problems solved by technology

[0005] In addition, in the existing laser-TIG arc hybrid welding, the defocusing amount of the laser beam is in a constant state; even if the scanning galvanometer laser is used, the scanning trajectory of the laser beam is realized on the surface of the workpiece, and the defocusing amount is basically kept in a constant state

In addition, the scanning galvanometer laser not only increases the beam transmission distance by designing the galvanometer inside the laser head, but also causes a certain loss of beam energy when the laser beam passes through the galvanometer.

[0006] In the process of high-power laser-TIG arc hybrid welding, when the laser defocus is zero, although the penetration of the laser beam is the strongest, the weld width on the back of the weld is also wide, but when the wall thickness of the welded workpiece is large, For example, when the workpiece wall thickness is 4mm ~ 8mm deep penetration welding of titanium alloy, the welding spatter is relatively large when the defocus is zero, and the undercut phenomenon on the front of the weld is also obvious.

When the above-mentioned high laser power is maintained, the laser defocus is negative and distributed in the range of -δ / 2 to -δ / 3. Although the welding process is more stable and the quality of the weld is better, the weld width on the back of the weld is slightly different. reduce

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