Aluminum alloy special-shaped structural part drilling and repair welding method

Abstract

The invention discloses an aluminum alloy special-shaped structural part drilling and repair welding method. The method comprises the following steps of 1, defect elimination, 2, defect positioning and drilling, 3, groove and hole finishing and cleaning, 4, repair welding area preheating, 5, repair welding and post-heating, and 6, weld seam finishing and X-ray fluoroscopy. Compared with the priorart, the method has the advantages that welding defects are eliminated through drilling, the digging area is small, the heat input time acting on a weld seam during repair welding is short, a weld seam melting pool is cooled and quickly crystallized, accordingly tiny air holes in the weld seam are crystallized without nucleation due to large supercooling degree, and therefore the welding qualifiedrate is ensured. Meanwhile, the repair welding area is small, welding stress is small, and therefore product welding deformation is small. By means of the drilling and repair welding method, the one-time repair welding qualified rate is greatly improved to 80%, and the period for treating the repair welding problem caused by repeated welding defect elimination of products is greatly shortened.

Description

technical field [0001] The invention relates to a drilling repair welding method for an aluminum alloy special-shaped structural member, in particular to a drilling repair welding method on a spherical surface five-way weld joint. Background technique [0002] The material of a structural part is LF12, the wall thickness is 3mm, and the weld joint is a "horseshoe" butt joint. Due to the limited space structure of the special-shaped structural part, the angle between the welding torch and the welding joint plane must be at a 65° posture to ensure welding; experience knows The angle between the welding torch and the welding joint plane is ≤85°, the welding seam protection effect is weak, and there are tiny pores on the weld seam that cannot be seen through by X-rays (that is, the pores below 0.3mm cannot be detected), especially at the edge of the weld seam. Allowed by design standards. However, due to the large defect excavation area in the conventional repair welding method...

AI Technical Summary

Problems solved by technology

However, due to the large defect excavation area in the conventional repair welding method, the heat input time acting on the weld seam is long during repair welding, and the tiny pores nucleate and grow up during the cooling and crystallization process of the molten pool at the edge of the weld seam, resulting in the formation of chain defects; At the same time, the special-shaped structural part is a thin-walled part, the conventional repair welding length is too long, the molten pool volume is too large, the horizontal and vertical shrinkage increases, welding deformation is easy to occur, the internal stress of the weld is large, and the crack tendency is large

[0003] The quality of repair welding directly affects the performance of the whole product; if a certain defect repair welding fails, the whole product will eventually be scrapped, which will cause incalculable economic losses and consume a lot of manpower and time costs

At present, there is no drilling repair welding method for special-shaped thin-walled parts

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