Optimization of Body-in-White Weld Parameters for DP590 and EDD Material Combination

Body in White (BIW) of an automobile serves as the shell, on which all the components that make up a vehicle, are mounted. The BIW is an assembly of press formed sheet metal components. The sheet metal composition of each component varies based on the form and functionality requirement of that component. The resulting assembly has multiple weld joineries with dissimilar compositions. The weld integrity of the joineries is crucial in maintaining the geometrical and structural integrity of the BIW. The primary welding method used in BIW assembly is Resistance Spot Welding (RSW). The quality of the weld is an outcome of a combination of multiple weld parameters. These parameters are majorly estimated based on the joinery thicknesses and material combinations. Multiple welding and testing iterations are done to fine tune the parameters for an optimum weld joinery. This is a very tedious process which increases the process time of a BIW assembly. This paper studied the impact of critical weld parameters and recommended the optimum parameter combinations. Real world combinations were emulated by evaluating dissimilar material combinations. Advanced high strength steel (DP590) with Extra deep draw (EDD) joineries with varying material thicknesses were considered for the study to represent the commonly used dissimilar composition combination. The optimized parameters for multiple combinations were concluded and results were discussed. The optimized parameters enable quick selection of optimum weld program for a given joinery or weld station and eliminate material wastage and time.