Plasma arc welding device and welding method for perforation with large penetration depth and large aspect ratio

Abstract

The invention relates to a large depth-of-fusion and large depth-to-width ratio perforated plasma arc welding device and a welding method, and belongs to the technical field of plasma welding. The welding device comprises a welding gun, the end part of the welding gun comprises a tungsten electrode, a porcelain sleeve is arranged on the outer side of the tungsten electrode in a sleeved mode, a water-cooled copper nozzle is arranged on the outer side of the porcelain sleeve in a sleeved mode, a gas cover is arranged on the outer side of the water-cooled copper nozzle in a sleeved mode, and protective gas is introduced between the water-cooled copper nozzle and the gas cover; a spiral flow guide groove is formed in the outer surface of the porcelain sleeve, ionized gas is introduced betweenthe porcelain sleeve and the water-cooled copper nozzle, the ionized gas flows between the inner wall of the water-cooled copper nozzle and the flow guide groove, the ionized gas flows out of the outlet of the water-cooled copper nozzle, and the ionized gas forms a vortex at the lower cavity of the water-cooled copper nozzle; the volume of the lower cavity of the water-cooled copper nozzle is smaller than the volume of the upper cavity, and the inner wall of the lower cavity is a streamline inner wall. The free stroke of the ionized gas is short, the directivity of the airflow is strong, so that it is beneficial to increase of the arc stiffness. Compared with an eddy current forming condition in an existing structure, the welding device has method has the advantages that the restrain of the eddy current is strong, the controllability good and the eddy current effect is obvious.

Description

technical field [0001] The invention relates to a perforated plasma arc welding device and a welding method with a large penetration depth and a large aspect ratio, belonging to the technical field of plasma welding. Background technique [0002] At present, the welding of large-thickness workpieces common in the industry is mainly by first processing the groove (V-shaped, Y-shaped, etc.), and then filling the groove with a multi-layer single-pass or multi-layer multi-pass welding method, thereby realizing welding. . However, this method requires pre-grooving, which not only causes waste of materials, but also takes time and labor, consumes a lot of manpower and material resources, and reduces production efficiency. In addition, the multi-layer welding welding process is complicated, and it is easy to cause welding defects. [0003] In the process of perforated plasma arc welding, after the arc is compressed by mechanical compression, thermal compression and electromagneti...

AI Technical Summary

Problems solved by technology

However, the existing perforated plasma arc welding technology can only penetrate the thickness of the workpiece in a single pass (generally less than 12mm), and the depth-to-width ratio is small (that is, the weld seam width is large, and the molten pool on the back is prone to collapse), which limits The industrial application of this advanced technology in the welding of large thickness workpieces

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