Effects of welding current and torch position parameters on bead geometry in cold metal transfer welding

This study investigated the effects of welding current and torch position parameters, including torch-aiming position, travel angle, and work angle, on bead geometry in single-lap joint gas metal arc (GMA) welding. High-speed filming and macrographs of weld cross section were used to observe the effect of each welding parameter on the properties of the bead geometry, including penetration, leg length, and toe angle. Response surface methodology was used to establish the relationship between the welding parameters and properties of bead geometry and to estimate regression models for predicting bead geometry. Both welding current and torch-aiming position were found to have significant effects on bead geometry, with strong linearity between them and bead geometry. The coefficient of determination (R2) of the estimated response surface models was 0.7226 for penetration, 0.8802 for leg length, and 0.8706 for toe angle. Further, experimental results indicate that the estimated models are very effective.