Gas Tungsten Arc Welding of Inconel 825 Sheet: Study on Weld Bead Geometry and GA Optimization

Abstract

In this work, gas tungsten arc welding (GTAW) on Inconel 825 is carried out which is a solid solution-based nickel-based alloy known for its excellent corrosion resistance properties and high strength. A Box–Behnken design (BBD) of 27 experimental runs was adopted for this study. Welding current (I), welding speed (V), gas flow rate (GFR) and arc length (N) are selected as process parameters to investigate different weld bead characteristics such as penetration (P), front width (FW) and front height (FH). Statistical models were developed using the RSM approach and model graph analysis is carried out for determining the influence of process parameters on the weld bead geometry. Finally, Genetic Algorithm(GA) is implemented to optimize the weld bead geometry of the welds. Results indicate, with an increase in welding current penetration and front width increases and decreases with an increase in welding speed. Results of GA provides an optimal perimeter combination of I = 120 A, V = 181 mm/min, GFR = 9.2 l/min and N = 2.4 mm, while considering the required penetration as 2.5 mm. Also, the results obtained using the GA approach is found beneficial for the fabrication industry.