Experimental Investigation of Combined Welding on Mild Steel

Welding is one of the important sectors in today�s industrial world. Welding is a positive metal joining process. It uses the principle of heat generation by pressure, heat and electric arc. TIG can produce the high quality weld and MIG has high efficiency of weld. In last two decades new processes and techniques have been implemented to take the advantages of both welding. First, hybrid welding developed but later on due to its handling difficulties, the combined welding is investigated. So, the project is related to the combined effect of TIG and MIG welding of mild steel plates. Welding current, gas flow rate, root gap, groove angle are taken as an input parameter. The tensile strength and hardness are response variable. Design of experiments by using Taguchi�s method has used to find the optimal set of parameters. Analysis of parameters on the response and their contributions has been studied.