TIG welding method applicable to moderately thick aluminum alloy

Abstract

The embodiment of the invention provides a TIG welding method applicable to moderately thick aluminum alloy. On the condition that beveling is not carried out, the effect of single-face welding and two-face forming effect is achieved. The connector mechanical property and welding efficiency can be greatly improved. The aluminum alloy TIG welding method is used for welding a weld joint between two workpieces and comprises the steps that an outer pressing block is adopted on the front faces of workpieces to be welded, a welding base plate with a welding leakage groove is arranged on the back faces of the workpieces to be welded to tightly support the workpieces, and therefore a weld joint to be welded of the two workpieces to be welded is right opposite to the center of the welding leakage groove; the two steps of backing welding and cosmetic welding are carried out, wherein the TIG welding is adopted for carrying out backing welding on the weld joint to be welded, so that welding leakage is formed on the back face of the weld joint to be welded, and direct forming is achieved; pulse polarity variation TIG welding is adopted for carrying out cosmetic welding.

Description

technical field [0001] The invention relates to aluminum alloy welding technology, in particular to a TIG welding method suitable for medium-thickness aluminum alloys. technical background [0002] In the aluminum alloy welding process, welding defects have a huge impact on the weld, such as incomplete penetration, incomplete fusion and other defects will directly lead to a significant reduction in the strength of the weld joint. [0003] Due to the particularity of aluminum alloy, such as the dense Al2O3 film formed during the welding process will prevent the fusion of basic metals and cause slag inclusions in the weld metal; oxides are easy to absorb moisture and form pores during welding, resulting in large pores; The linear expansion coefficient and crystallization shrinkage rate are about 2 times larger than those of steel, which will produce large welding deformation and internal stress. For rigid structures, improper technology will cause cracks; liquid aluminum can d...

AI Technical Summary

Problems solved by technology

Multi-layer multi-pass welding will increase the difficulty of cleaning between layers, and multiple welding will increase the probability of welding defects and affect welding quality

[0006] For TIG argon arc welding after beveling, when a large welding speed is required, the welding current and heat input need to be increased significantly, resulting in welding shrinkage deformation and residual stress, and when welding medium and thick plates, the shape of the weld Large coefficient, wide and shallow weld seam, which is not conducive to the final surface covering welding

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