Application of Taguchi Design Method for Parametric Optimization of MIG Welding

Abstract

In the various engineering field like aerospace, nuclear and underwater applications, scope of Metal Inert Gas (MIG) welding, has increased to a greater extent. As a result, to improve the existing process of welding, different parameters are needed to be investigated. The MIG welding parameters are the most important factors that affect the quality, productivity and cost of welding. This report presents the study of the influence of different welding parameters on the ultimate tensile strength of the weld. The significance of each parameter is investigated using Taguchi Analysis and the method is also employed to study the welding characteristics of material and optimization of the welding parameters. The Analysis for signal-to-noise ratio is done using MINITAB-18 software for higher-the-better criteria. In the present work, MIG welding has been performed on low carbon steel with mild steel copper coated welding wire, suitable for CO2 gas protective electrode of 1.2 mm diameter. An experiment has been designed using Taguchi’s Orthogonal Array L16, taking welding current, gas pressure and welding speed as factors having four levels each. The selected levels for welding current are 145A, 155A, 168 A, 175A, for gas pressure are 14psi, 21psi, 28psi, 36psi and for welding speed are 13cm/min, 15cm/min, 17cm/min, 19cm/min. The optimal set of process parameters for optimal response of tensile strength (408.73 N/mm2) is found to be 155A welding current, 14psi gas pressure, and 17cm/min welding speed at economic level. The optimal values of individual quality characteristics have been confirmed by conformation experiment using the optimal levels of process parameters and then comparing the predicted values of quality characteristics with the actual ones.