Comparative Investigation of Mechanical Properties in GMAW/GTAW for Various Shielding Gas Compositions

Gas metal arc welding (GMAW) and gas tungsten arc welding (GTAW) are extensively used in the areas requiring high-speed welds, higher weld quality finishes, and superior strength properties. In this experimental study, the influence of shielding gas composition on the mechanical properties of austenitic stainless steel 316L was investigated. The selection of shielding gases and current intensities is the major concern to achieve the intended properties of the weld metal. The influence of four various shielding gas compositions was studied in this work. It was carried out in both GMAW and GTAW for 3 and 6 mm thick plates. Optimization of shielding gas mixtures, current intensities, flow rates, and welding speed is required to automate the process and to improve the overall efficiency of the weld process. Mechanical properties are analyzed for GTAW and GMAW specimens. The obtained results prove that the tensile strength, hardness, and impact strength are higher for GTAW weld specimens compared to GMAW weld specimens. Further by decreasing the percentage of CO2, the tensile strength and hardness values give the superior results.