Laser-electric arc composite heat source high-speed welding method of ultrahigh strength steel

Abstract

The invention relates to a laser-electric arc composite heat source high-speed welding method of ultrahigh strength steel, belonging to the technical field of high-strength steel welding. The traditional laser-electric arc composite heat source high-speed welding method of the high-strength or ultrahigh strength steel has overhigh welding linear energy due to low welding speed and large energy input so as to cause the deformation of a welding workpiece; in addition, chevilled silk spacing is overlarge, and stabilization action realized by a laser is reduced because the laser is adopted firstly and the electric arc is adopted subsequently so that a welding process is unstable and easy to generate splashing. The invention adopts laser-electric arc composite heat source welding; the welding workpiece is the high-strength steel or the ultrahigh strength steel; an electric arc welding gun is used for welding firstly and a laser nozzle is used for welding subsequently during welding; the current of electric arc welding is 140-180A, and the voltage of the electric arc welding is 23-25V; an included angle theta between the electric arc welding gun and the surface of the workpiece is 60-65 degrees; the laser power is 3-5kW; the welding speed v is 1-3m / minute; and the chevilled silk spacing h between a laser beam and a welding stick is determined within a range of 1-3mm. The invention realizes the welding of the ultrahigh strength steel without preheating, cold cracks or deformation.

Description

technical field [0001] The invention relates to a laser-arc composite heat source high-speed welding method for ultra-high-strength steel. The arc is preheated first, and the laser is welded at a high speed, which can significantly reduce the welding deformation of the workpiece, significantly reduce the tendency of cold crack cracking in the welding of ultra-high-strength steel, and improve welding. quality. The method belongs to the technical field of high-strength steel welding. Background technique [0002] When arc welding is used to weld high-strength steel, the workpiece will be deformed to a certain extent, including lateral and longitudinal shrinkage deformation, angular deformation, bending deformation and wave deformation, resulting in variation in the shape of the welded structure, a decrease in dimensional accuracy, a decrease in bearing capacity and a decrease in fatigue strength. Such welded structures will fail early due to additional bending moments and str...

AI Technical Summary

Problems solved by technology

However, this solution also has some defects: first, the welding speed is slow and the energy input is large, resulting in excessive welding line energy, which will cause deformation of the welding workpiece; When the arc is behind, the role of the laser to stabilize the arc is reduced, making the welding process unstable and prone to spatter

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