Method for vertical double-sided double-arc plasma symmetry welding

Abstract

The invention relates to the field of welding processing and discloses a method for vertical double-sided double-arc plasma symmetry welding. The method comprises the following steps: vertically placing a workpiece along the direction of a welding line; horizontally arranging variable polarity plasma arc welding guns, metal inertia gas welding guns, or non-consumable electrode metal inert-gas arc welding on two sides of the front and back two sides of the workpiece respectively. The method has the advantages of small current, high deposition rate, stable arc combustion, radical elimination of lack of penetration, maximum reduction of welding deformation, and contribution to acquisition of high-quality welding lines.

Description

technical field [0001] The invention relates to the field of welding processing, in particular to a plasma symmetrical welding method. Background technique [0002] In recent years, with the continuous and rapid development of industries such as aerospace, high-voltage switches, and high-speed railways, a large number of non-ferrous metals such as aluminum and aluminum alloys have been used. Aluminum alloys have been widely used in these industries because of their small specific gravity and high strength. However, due to the sensitivity of aluminum alloy welding, there are often shortcomings such as many inspection procedures, high porosity, large welding deformation, and low joint strength coefficient (only 0.6 to 0.8 of the base metal). [0003] At the same time, with the variety of products, structures, materials, and service conditions, the requirements for welding quality are getting higher and higher, and the welding workload is gradually increasing. An efficient wel...

AI Technical Summary

Problems solved by technology

There are many processes and quality control links. For thicker plates, beveling must be done first, and the processing is time-consuming and laborious;

[0008] 2) The overheating of the weld seam is serious, the joint strength is obviously low, and the weld seam area is prone to brittleness

Once there is a small defect, there will be cracks in the long-term work;

[0009] 3) The workpiece is seriously deformed

The weld seam and the heat-affected zone are obviously subsided, and the shape needs to be corrected after welding, and the processing procedure is increased;

[0010] 4) The width of the weld seam seriously exceeds the standard;

There are greater risks in the quality and deformation of the weld seam, and the production cycle is relatively longer

[0012] 6) The overall efficiency is low and cannot meet the needs of mass welding production

[0016] 1) In order to ensure the good fluidity of the metal in the aluminum alloy molten pool, it is necessary to adopt the AC method of removing the oxide film during the negative reverse polarity period of the weldment, but it will cause serious burning of the tungsten electrode, resulting in unstable arc combustion

[0017] 2) Arc stabilization measures must be taken for the AC plasma arc, which not only increases the complexity of the equipment, but also easily produces double arcs

[0018] 3) Since the plasma arc has almost no cleaning effect on the oxide film on the back of the weldment, the flow of liquid metal on the back of the perforated molten pool will be affected by the oxide film on the back of the weldment. Difference

[0019] 4) Due to the large specific heat capacity, thermal conductivity and heat of fusion of aluminum alloy, the low-frequency pulse perforation type plasma arc welding of "one pulse and one hole" used in welding steel to improve the stability of weld formation cannot be well Applied to aluminum alloy welding

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