Analysis of Shielding Gases Influences 304 Gas Metal Arc Welding Microstructure, Weld Geometry, and Mechanical Properties

Shielding gases had considerable significance in welding metal protection from contamination during welding.Welding protection gas is essential in welding joint quality, connected to the arc characteristics and weldment microstructure.Understanding the influence of welding shielding gas in different metal welding processes is extremely important, and many research papers and experiments have been performed.The current study objective is to analyse and summarize shielding gas variations' effects on welding joint bead geometry, dilution percentage, joint soundness, and microstructure by examining the impacts of different protection gas combinations on AISI 304 stainless steel MIG welding.Three AISI 304 weldment samples were welded with MIG technology and 308L filler wire, and three different gas mixtures as protection gas; the dilution percentage for every sample was calculated to evaluate gas mixture influence on heat concentration on welding zone geometry calculation-ferrite percentage and calculated to estimate and predicate the final welding microstructure and texture.An optical microscope and SEM were employed to reveal weldment microstructure, welding porosity, and defects and study their impact on mechanical properties.Vickers microhardness and tensile tests were done to record gas mixture effects on welding zone hardness and strength.Variation in gas mixture effects on weldments' corrosion resistance was recorded using a corrosion test on every welding sample.These research results can be used as guidelines to achieve the required welding quality in practical welding and provide an excellent foundation for understanding and solving shielding gas issues in the metal welding industry and evaluating welding protection gas mixtures' productivity and quality.The heat input of the three samples is equal due to the use of the same voltage, current, and travel speed; for that, we need to profoundly analyse the weldments microstructure and analyse the impacts of variation in microstructure, which resulted from protection gas mixture effects on the cooling rate on weldments mechanical properties.It fits with the requirements of design criteria.