Most of the occurrence of welding deformation is caused by the asymmetry of heat generated by welding and the expansion caused by different heat. Now we have sorted out several methods to prevent welding deformation as follows for reference:
1. Reduce the cross-sectional area of the weld and use a smaller bevel size (angle and gap) as much as possible while obtaining complete and no defects in excess of the standard.
2. Use welding method with small heat input. Such as: CO2 gas protective welding.
3. Use multi-layer welding instead of single-layer welding whenever possible when welding thick plates.
4. When the design requirements are met, the welding of longitudinal reinforcement ribs and transverse reinforcement ribs can be performed by intermittent welding.
5.When both sides can be welded, double-sided symmetrical bevels should be used, and a welding sequence that is symmetrical to the neutral and axial components should be used during multi-layer welding.
6. When the T-shaped joint plate is thicker, open bevel angle butt welds are used.
7. Use the anti-deformation method before welding to control the angular deformation after welding.
8. Use rigid fixture fixture to control post-weld deformation.
9. Use the reserved length method of the component to compensate for the longitudinal shrinkage and deformation of the weld. For example, 0.5~0.7 mm can be reserved per meter of H-shaped longitudinal weld.
10. For distortion of long members. It mainly relies on improving the flatness of the board and the assembly accuracy of the components to make the bevel angle and clearance accurate. The direction or centering of the arc is accurate so that the weld angle deformation and the longitudinal deformation values of the wing and web are consistent with the length direction of the component.
11. When welding or installation of components with more welds, a reasonable welding sequence should be adopted.
12. When welding thin plates, use in-water welding. That is, the molten pool is surrounded by protective gas in water, and the nearby water is completely removed from the gas to ensure that the welding is carried out normally. By using this method, the metal around the solid melt pool is cooled by water in time, and the deformation amount is controlled to a very small extent (the circulating coolant is added opposite the welding side to take away the heat generated by welding).
13. Multi-stage symmetrical welding, that is, welding one section, stop for a while, welding to the opposite side, stop for a while.
Post time: Mar-10-2025