Effect of Plate Placement on Nugget Shape in Joining Dissimilar Thickness Automotive Steel Thin Sheets Using Resistance Spot Welding

The automotive products are adopting modern design dynamics to meet the market demands. One of the challenges that the automotive industries are facing is joining dissimilar thickness steel panels. The current study is an attempt to understand the formation of nugget shape during the resistance spot welding process in joining dissimilar thickness automotive steel AISI 4340. Steel plates with two different thickness of 2 mm and 1.5 mm are considered in the current investigation. The numerical simulation of the resistance spot welding process is carried out in FEM based commercially available software package. The study revealed that the temperature and the shape of the nugget is not same with the alteration of the positioning of the steel plates having dissimilar thickness. The shapes of the nuggets are different when the plate with higher thickness is at the top than the nugget formed when the plate is placed at the bottom.