Laser scanning-TIG composite melting strip welding method

Abstract

The invention discloses a laser scanning-TIG composite melting strip welding method. The laser scanning-TIG composite melting strip welding method comprises the following steps: during welding, a strip-shaped welding wire with a rectangular section is used; a strip conveying mechanism conveys the strip-shaped welding wire into the space above a gap of a workpiece to be welded; the width directionof the strip-shaped welding wire forms a certain angle with a welding direction; one end of a TIG welding gun is connected with a positive pole of an output end of a power supply; the strip-shaped welding wire is connected with a negative pole of the output end of the power supply; a laser beam scans in the welding direction; one half of a scanning area is located in the strip-shaped welding wire,and the other half is located in a molten pool; and a laser scanning path has different manners according to different materials and welding requirements. According to the laser scanning-TIG composite melting strip welding method, the mutual coupling action of laser and an electric arc is improved; the stirring action of laser on the molten pool is improved; the shortage of driving flow in the molten pool by virtue of surface tension purely is made up; the solidification time of the molten pool is prolonged; and the temperature gradients of molten drops and the molten pool and the impact of the molten drops on the molten pool are reduced, so that the escape of bubbles is benefited, and the formation of crystallization cracks is suppressed.

Description

technical field [0001] The invention belongs to the field of welding technology, in particular to a laser scanning-TIG composite melting ribbon welding method. Background technique [0002] Laser welding is a process in which a focused laser beam is used as a source of moving heat to join metal parts. The focused laser beam has a high power density, and has the characteristics of fast welding, large penetration depth, and narrow heat-affected zone. Laser welding is more and more widely used in automotive, aerospace, defense industry, shipbuilding, marine engineering and other fields. [0003] Laser-TIG arc hybrid welding, by applying an electric arc near the laser beam, thereby reducing the electron density, diluting the plasma cloud, reducing the consumption of laser energy, and significantly improving the laser absorption rate of the workpiece. Moreover, since the laser absorption rate of the workpiece increases with the increase of temperature, the arc preheats the weld...

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Problems solved by technology

[0006] Aiming at the problems of laser-TIG composite filler wire welding with high assembly precision, poor gap adaptability, and unstable welding process, a laser scanning-TIG composite melting ribbon welding method was proposed.

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