3D printing remanufacturing process and system for nuclear power plant flange

Abstract

The invention relates to a 3D printing remanufacturing process and system for a nuclear power plant flange. The method comprises the following steps: removing metal of a flange defect part; scanning the flange and a to-be-repaired area of the flange, establishing a three-dimensional model, planning weld joint configuration of the to-be-repaired area of the flange, generating a robot welding path,guiding the robot welding path into a robot controller, conducting priming coat welding based on plasma arc welding firstly, then filling a cover surface by gas shielded welding, and relieving stresson the weld joints after processing of each layer of weld joints is finished. The system comprises a scanning part, a model analysis part, a robot controller, a robot and a working table. The method is based on robot 3D printing repair, the whole welding sequence and direction are reasonably arranged, welding automation is realized, heavy manual welding work is omitted, relative balance of weldingheat input of the whole component is achieved, the purpose of controlling welding deformation is achieved, the weld joint heat affected zone can be controlled to be smaller than that of a manual welding method, and the residual stress of the weld joints is controlled to be within a relatively small range.

Description

technical field [0001] The invention relates to the technical field of nuclear power equipment maintenance, in particular to a 3D printing remanufacturing process and system for flanges of nuclear power plants. Background technique [0002] Most nuclear power plants are located by the sea and rely on a large amount of seawater for cooling. In the seawater cooling system of nuclear power plants, large-diameter flanges are often damaged due to gasket damage, which leads to corrosion on the end faces of the flanges, and in severe cases, media leakage. Maintenance strategies generally consider replacing spare parts or repairing them before use. However, the production cycle of large-diameter flanges is long, which leads to the lack of spare parts in power plants in some cases, so they will choose to use the strategy after repairing. Reuse after repair is divided into online repair and offline repair. Generally, small-area (corrosion) defects are repaired online, which can meet ...

AI Technical Summary

Problems solved by technology

[0003] At present, the off-line repair of this kind of flanges uses manual welding to repair the missing parts of the metal. Multiple welders weld at the same time, and the welding heat-affected zone, welding deformation and welding residual stress cannot be effectively controlled, and the areas where the control is not in place may be The origin of the next defect

[0004] Specifically, for the off-line maintenance of large-diameter flanges in this kind of nuclear power plant, the metal on the defective part of the flange is first excavated, and then the surface inspection is performed to confirm that the defects have been completely removed, and then a number of welders perform repair welding on the defective part, because Everyone needs a certain space for operation, and the speed and sequence of manual welding are directly determined by the operator according to his habits, so the heat-affected zone, welding deformation and welding residual stress of flange repair cannot be effectively controlled

[0005] Manual welding repair methods for defect areas are generally manual tungsten argon arc welding and manual electrode arc welding. The welding heat sources of these two methods are relatively scattered, and the welding heat-affected zone is relatively large. Moreover, continuous welding in local areas will make the welding heat-affected zone larger.

[0006] The manual welding repair defect area is continuously welded from one side to the other side, and the welding bead arrangement will not be balanced according to the distribution of the defect area, resulting in relatively large welding deformation

[0007] Welding residual stress cannot be avoided, but can only be reduced. Commonly used technological measures to control residual stress during the welding process include: reasonable welding sequence and direction, hammering the weld seam, and under the condition of multiple people repairing welding at the same time, each person is responsible for one area , cannot be arranged globally, and the hammering of one weld seam will affect other areas and cannot be welded, so these two measures cannot be realized

Images