Lossless reduction method of welding residual stress of high-strength aluminum alloy large thin-wall storage box

Abstract

The invention discloses a non-destructive reduction method for welding residual stress of a large-scale thin-walled high-strength aluminum alloy storage tank. The material of the storage tank is 2219 aluminum alloy which has been subjected to solid solution treatment after cold rolling and artificial aging treatment, and comprises the following steps: (1) ) Connect the stress relief equipment system and set parameters, (2) The ultrasonic transducer converts the electrical signal generated by the ultrasonic generator into a high-power ultrasonic wave, and directly injects the couplant into the welding joint of the tank that needs stress relief treatment, (3) Detect the residual stress value of the treated part, and carry out welding residual stress reduction treatment according to the actual situation. The present invention uses a high-power ultrasonic transducer to convert the electrical signal generated by the high-power ultrasonic generator into a high-power ultrasonic wave, and directly injects the coupling agent into the welding joint of the storage tank, and activates the lattice arrangement in the stress zone material of the welding joint through the power ultrasonic, Induces dislocations to detach from pinning, promotes microscopic plastic deformation, and realizes the reduction of residual stress inside the workpiece material.

Description

technical field [0001] The invention relates to a method for eliminating stress, in particular to a method for non-destructively reducing the welding residual stress of a high-strength aluminum alloy large-scale thin-walled storage tank. Background technique [0002] At present, the storage tank has a large structural size and is a thin-walled part. The thinnest area is only 1.5mm thick. It is spliced ​​by fusion welding (TIG) and friction stir welding (FSW) by the middle tube section of the tank, the ellipsoid bottom and the cone bottom. , There are various forms of welding structure, especially the complex structure of ellipsoid bottom and cone bottom and its flange. [0003] The material of the storage tank is 2219 aluminum alloy, which is usually subjected to solid solution + artificial aging treatment at no more than 200°C after cold rolling. The strengthening effect is formed by the aging precipitation of AlCu phase, and good material properties are obtained. It is a k...

AI Technical Summary

Problems solved by technology

Due to the large volume and thin wall of the tank structure, especially the complex welding structure of the flange, the mechanical methods such as impact and hammering to reduce the stress have poor accessibility, which can easily lead to damage or even damage to the components, and generally can only be used to remove residual stress on the surface. Stress reduction treatment; in order to achieve better stress reduction effect, the heat treatment method must be heated to above 300° and keep warm for a certain period of time. This temperature exceeds the aging temperature of the storage tank material 2219, which will reduce the performance of the storage tank material and easily lead to The box is deformed and the process is complicated, so it is not suitable for the residual stress reduction treatment of the welded structure of the thin-walled aluminum alloy box; the vibration aging is suitable for the overall stress relief treatment of large components, because the welding structure of the tank ellipsoidal bottom and conical bottom flange has various forms , the residual stress distribution of each structure is different, and it is necessary to carry out targeted treatment according to the stress state of the specific flange structure in order to ensure the reduction effect of the residual stress of all flange structures, so the vibration aging cannot be selective and targeted for the local structure of the tank processing, poor flexibility

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