The reason and prevention of welding robot welding deformation and stress
The welding deformation methods include shrinkage deformation, angular deformation, bending deformation, wavy deformation and distortion deformation. During the whole welding process, uneven heating and cooling of the weldment is the direct cause of welding stress and deformation. The key processing measures to reduce welding stress and deformation are:
1. The embedded shrinkage deformation is calculated based on basic theory and social experience. The shrinkage capacity is considered in advance during the preparation and production of weldment materials, so that the steel parts after welding can achieve the specified appearance and specifications.
2. The anti-deformation method is based on basic theoretical calculations and social experience to estimate the orientation and size of structural welding deformation in advance, and then give a preset deformation with the opposite orientation and the same size during welding installation to offset the deformation caused by welding.
Third, the rigidity fixed immobilization method. When welding, the stiffness of the weldment is fixed in many aspects. After welding, the weldment is cooled to the room temperature before removing the stiffness and immobilization, which can reasonably avoid angular deformation and wave pattern deformation. This method will increase the welding stress and is only suitable for high-carbon steel structures with good plastic deformation.
4. Choose an effective welding sequence to make the weld shrink as much as possible. When welding parts with many welds, the separated short welds must be welded first, and then the long welds must be welded directly to prevent cracks at the joints of the welds. If the welding seam is long, the gradual withdrawal welding method and the skip welding method can be used to make the temperature more uniform throughout, thereby reducing the welding stress and deformation.
Fifth, hammering weld method In the whole process of welding seam cooling, a round iron hammer is used to hammer the weld seam symmetrically and quickly, causing plastic deformation and widening of the metal material, which offsets part of the welding shrinkage and deformation, thereby reducing welding stress and deformation .
6. Before welding by heating the "reduction zone" method, carry out heating in the surrounding area of the welding position (referred to as the reduction zone) to extend it. When cooling after welding, the heating zone shrinks together with the weld, which can be reasonably reduced Welding stress and deformation.
7. The purpose of heating before welding and slow cooling after welding is to reduce the temperature difference between the weld area and other parts of the weldment, reduce the cooling rate of the weld area, so that the weldment can be cooled more evenly, thereby reducing welding stress And deformation.
