Evaluation of the Use of Adhesive Tape in Laser Welded Ultra-High-Strength Steel Lap Joints

In this study, use of adhesive double-sided tape in laser welded ultra-high-strength steel lap joints was evaluated. The test material in the study was abrasion resistant steel (AR400). Optical microscopy was used to investigate macroscopic morphologies of the welds and hardness profiles were measured. Static properties of the joints were evaluated by performing tensile shear strength tests. Fatigue strength of the joints were evaluated by conducting axial fatigue tests. The use of tape resulted in a gap between the welded plates which has several advantages. The gap between the plates markedly increased the width of the weld at the interface of the plates. According to the hardness measurements the hardness of the weld metal was 12% higher compared to the hardness of the AR steel base material. The gap between the plates increased the strength of the joint by up to 20%. The adhesive tape itself did not have a significant effect on the shear strength of the joints. The main advantages of using the tape were a constant air gap and its function as a fastener in welding, so that separate fasteners are not needed.