Effect of GTAW on the Tensile Strength and Hardness of Mild Steel

Gas tungsten metal arc welding (GTAW) is used to study the effect of the base metal thickness, welding current and welding speed on the tensile strength and hardness of mild steel welding. The analysis found that base metal thickness had the highest effect and highest means of tensile strength and hardness of the welding. Taguchi’s design (TD) suggested using higher base metal thickness, lower welding current and higher welding speed when welding mild steel in order to obtain maximum tensile strength and hardness. The welding that has higher tensile strength showed higher hardness. However, the hardness increased proportionally with the increased internal stresses of the welding. The welding showed wider heat affected zone (HAZ) with the increase in internal stresses of the welding.