What are the causes of crane welding deformation

        The crane is a lifting equipment that is horizontally framed over the workshop, warehouse and material yard for material lifting. Because its two ends are located on tall concrete columns or metal supports, it looks like a bridge. Cranes are widely used in engineering and production, but many problems will occur during use.

　　 The welding deformation of the crane was discovered during the maintenance process, and the control of the deformation became an urgent problem to be solved. Because the cross-sectional shape of the crane is a typical box girder structure, it has many welding seams, complex structure, and large welding stress and deformation. If a reasonable design and construction process plan is not adopted, deformation will occur during the welding process, which will seriously affect the welding quality, and even cause the structure to be unable to be installed and used correctly.
       To control welding deformation, it is important to fully understand the cause of the deformation, which is helpful to take appropriate measures according to the specific situation to reduce the degree of welding deformation to a small value, so that the structure can be used correctly and reasonably, and the crane can be better improved. The various performances of the machine provide a guarantee for better construction.

　　 Normally, the main cause of welding deformation of cranes is uneven heat input. The amount of heat input is closely related to the material and structure of the welding. Material factors and structural factors affect the movement of the metal around the heat source, causing it to be affected by both internal and external binding forces, resulting in welding materials. Stress deformation.

　　 Welding deformation mainly includes shrinkage deformation (longitudinal shrinkage and lateral shrinkage), bending deformation, angular deformation, wave deformation, twisting deformation and other types. It is reflected in the external structure of the crane to show local uplift, distortion, bending and twisting.
There are many reasons for these problems during the welding process. For example, the size of the weld is not accurate enough, the number of welds does not meet the predetermined standard, and there are large errors in the welding position and the design position. The welding material The thermophysical properties are not strong, the construction process is not conducive to achieving a good welding state, welding parameter selection, etc., each specific link must be carefully grasped to achieve the desired effect.