Welding device for inhibiting welding hot cracks and welding system

Abstract

The invention provides a welding device for inhibiting welding hot cracks and welding system. The welding device comprises a first fixing plate, a second fixing plate, a pneumoelectric slip ring, a hollow shaft driving unit, a conductive connecting rod and supporting rods, wherein the first fixing plate and the second fixing plate are arranged at an interval; the pneumoelectric slip ring is connected with one side, facing the second fixing plate, of the first fixing plate, and the hollow shaft driving unit is connected with one side, facing the first fixing plate, of the second fixing plate; the conductive connecting rod is connected with the hollow shaft driving unit and penetrates through the second fixing plate; the bent contact tube is connected with the conductive connecting rod on the outer side of the second fixing plate; the plurality of supporting rods are evenly distributed in the rotating axial direction of the hollow shaft driving unit and connected with the first fixing plate and the second fixing plate respectively; and the hollow shaft driving unit drives the conductive connecting rod to rotate, and the conductive connecting rod drives the bent contact tube to swing. Flow of liquid metal is promoted through electric arc swing, the grain structure of a welding seam is refined, segregation of impurity elements is reduced, the liquid metal flows back to a heat affected zone grain boundary liquefaction zone from a molten pool zone, generation of cracks is reduced, and the crack propagation resistance is increased.

Description

technical field [0001] The invention relates to the field of welding technology, in particular to a welding device and a welding system for suppressing welding thermal cracks. Background technique [0002] Aluminum alloy materials have the advantages of high specific strength, good plasticity, and corrosion resistance. They are widely used as lightweight load-bearing structures in rail transit, high-speed rail, and aerospace, and play an important role in the field of lightweight vehicles. Welding hot crack is a welding defect that is easy to occur in the welding process of aluminum alloy. The fluidity of the liquid metal in the welding pool, the microstructure of the weld, and the dispersion state of the eutectic with a low melting point have a significant impact on the generation of welding hot cracks. During the welding cooling process, the weld and its heat-affected zone metal at the tail of the molten pool are in the solid-liquid coexistence stage, and the solidified d...

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Problems solved by technology

[0003] The invention provides a welding device for suppressing welding thermal cracks, which is used to solve the problem that in the existing welding process, when the dendrites are developed and the fluidity of the liquid metal is weak, the liquid metal will stay between the dendrites, resulting in poor plasticity. If the liquid film is subjected to tensile strain, it is easy to form cracks, and the thicker the weld structure, the more obvious the directionality of the columnar crystals; the impurity elements segregate at the grain boundaries to form a low melting point eutectic, which is prone to welding hot crack defects , promote the flow of liquid metal through arc swing, refine the grain structure of the weld, reduce the segregation of impurity elements, and make the liquid metal flow back from the molten pool area to the grain boundary liquefaction area of ​​the heat-affected zone, reduce the generation of cracks, increase Crack propagation resistance, so as to suppress the occurrence of aluminum alloy welding thermal cracks

[0004] The present invention also provides a welding system to solve the problem that in the existing welding process, when the dendrites are developed and the fluidity of the liquid metal is weak, the liquid metal will stay between the dendrites and form a liquid film with poor plasticity. If subjected to the action of tensile strain, it is easy to form cracks, and the thicker the weld structure, the more obvious the directionality of columnar crystals; impurity elements segregate at the grain boundaries to form eutectics with low melting points, which are prone to welding hot crack defects. Stir the molten pool of aluminum alloy welding to increase the fluidity of the liquid metal: refine the weld structure, reduce element segregation, disperse and intermittently distribute the low melting point eutectic, and reduce the generation of cracks; disrupt the crystallization of columnar crystals Direction, breaking the continuity of the liquid film, increasing the resistance of crack propagation; promoting the return of liquid metal to the gap between dendrites, and promoting the healing of cracks

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