How to Reduce Workpiece Deformation Defects in Rivet Welding Processing?

How to Reduce Workpiece Deformation Defects in Rivet Welding Processing?

Workpiece deformation is one of the most common quality defects in rivet welding processing. Mainly caused by welding thermal stress, assembly errors, uneven cooling and non-standard operation processes, it usually manifests as bending, twisting, angular deformation and dimensional deviation. These problems not only affect the assembly accuracy of structural parts, but also reduce the overall load-bearing stability. In actual rivet welding production, scientific measures including pre-processing optimization, process improvement, tooling assistance and standardized operation can effectively reduce the probability of workpiece deformation and greatly improve the finished product qualification rate.

Optimize blanking and pretreatment to eliminate hidden deformation risks from the source. Strictly perform precision blanking according to construction drawings to ensure regular dimensions of plates and profiles and avoid assembly deviation caused by irregular cuts and uneven margins. Thoroughly remove rust, oil stains and oxide scales on the workpiece surface to prevent uneven welding caused by impurities. For thick plates and special-shaped components, annealing and stress relief pretreatment can be implemented in advance to release internal stress of raw materials and avoid natural deformation during subsequent processing and service.

Adopt tooling positioning and riveting fixing processes to limit welding displacement. Special tooling fixtures and positioning molds shall be used for batch and large-scale component processing to lock dimensional accuracy and flatness and prevent loosening and displacement during welding. Riveting positioning and spot welding fixing are preferred for pre-fixing structures. Uniform multi-point positioning disperses stress instead of direct full welding, which effectively reduces twisting and bending deformation caused by thermal expansion and contraction during welding.

Optimize welding techniques to balance thermal stress. Adopt segmented welding, symmetrical welding and skip welding to avoid long-time continuous welding at a single position, which leads to excessive local temperature and uneven thermal deformation. Adjust welding current and speed precisely according to plate thickness to prevent incomplete welding from fast operation and overheating deformation from slow operation. Thin plates apply low-current and short-arc fast welding, while thick plates adopt layered welding and gradual cooling to ensure uniform overall heating and minimize thermal stress deformation.

Standardize cooling methods and post-welding correction to complete quality control procedures. Avoid rapid water cooling or forced air cooling after welding; workpieces shall be cooled naturally and slowly to prevent deformation and cracking caused by excessive temperature difference. Slightly deformed workpieces can be leveled accurately through mechanical cold correction or local thermal correction to repair dimensional errors. Establish a complete post-inspection system to check flatness and verticality after welding, eliminate minor deformation defects in advance, and ensure that rivet welding workpieces feature accurate dimensions and stable structure to meet assembly and operational standards.