Sensitivity analysis of submerged arc welding parameters for low alloy steel weldment

It is very tedious to characterize the bead geometry of welding process due to complex existence of parameters that affect weld quality. Researchers have attempted to predict weld bead characteristics including bead size and shape, using various experimental parameters such as welding speed, welding current, arc voltage etc. However, the results of these studies tend to be limited to a specific process parameter range and to certain materials. In this article, the effects of welding process parameters on welding current, arc voltage, welding speed and electrode extension on weld bead geometries and percentage of dilution of submerged arc welding (SAW) on A516 grade 70 carbon steel is presented. Taguchi method which is a systematic optimization method for design and analysis of experiments is introduced to acquire optimum weld conditions. Multiple curvilinear regression models are developed to analyze the effects and interaction of each weld process parameter on the weld bead geometries and dilution. Sensitivity analysis is performed to study detailed characteristics of the weld bead. Results also reveal that the bead reinforcement is almost non-sensitive to the variations in welding current and welding speed.