Welding method for gas shielded welding of aluminium-alloy vehicle body

Abstract

The invention discloses a welding method for gas shielded welding of an aluminium-alloy vehicle body. The welding method comprises the following specific steps of: in welding, spraying a layer of pasty welding agent on an assembled welding seam base material in advance, wherein the pasty welding agent is 10-15mm in width and 50-200mum in thickness; when the welding agent entering a low-temperature area at the periphery of the temperature field of the arc reaches the melting temperature (560 DEG C) along with the movement of welding arc along the direction of a welding seam, immediately melting the welding agent into a liquid film, quickly wetting the surface of the base material, removing an oxidation film on the surface of the base material, and then covering the surface of the base material and the surface of metal in a molten pool. The welding method disclosed by the invention has the advantages that the welding process can be finished only by using the heat inputted in arc welding to melt the base material with the melting point of being 570-640 DEG C and welding wires as electrodes; aluminium-alloy MIG gas shielded welding connection of the high-strength vehicle body can be realized only by inputting low heat, the process is excellent, and the performance of joints is stable and good.

Description

technical field [0001] The invention belongs to the technical field of aluminum alloy gas-shielded arc welding welding materials, and in particular relates to a welding method for gas-shielded welding of aluminum alloy car bodies. Background technique [0002] In recent years, with the adjustment of my country's automobile industry policy and the implementation of new energy policy and low-carbon environmental protection policy, as well as the development of high-speed and efficient transportation of rail vehicles, high-strength, high-toughness, corrosion-resistant aluminum alloys are used to replace steel, and thin-walled Complex section aluminum profiles and thin plate stamped aluminum structural parts have become the main way to realize the weight reduction of car bodies as car body materials. Since car body manufacturing is an industry in which welding is the leading process, the depth of development of aluminum alloy car body manufacturing has promoted the rapid developm...

AI Technical Summary

Problems solved by technology

Fourth, due to the excessive heat input of the welding arc, the range adjacent to the heat-affected zone of the weld is larger and the influence is deeper, resulting in a too low strength of the heat-affected zone of the weld, which is only 60%-70% of the strength of the base metal itself. The strength of the aluminum alloy strengthened by heat treatment is reduced more, in order to maintain the bearing capacity of the workpiece in the process design, the base metal has to be thickened technologically

Fifth, due to excessive heat input, metal evaporation and dust generation increase, environmental protection and other problems occur

[0006] Due to the above-mentioned comprehensive reasons, the traditional aluminum alloy arc welding technology, on the one hand, wastes too much high-quality raw materials for manufacturing the car body and valuable post-welding processing man-hours, on the other hand, it also greatly prolongs the product production cycle, and the product quality is not high. It also reduces the weight reduction effect of the car body, which directly affects the development of the aluminum alloy car body manufacturing industry.