Taguchi optimization of metal inert gas (MIG) welding parameters to withstand high impact load for dissimilar weld joints

Abstract

The welding of two different kinds of metals has found greater applications and use in several fields of manufacturing in present days. A387 is a sort of grade steel used in the fabrication of pressure vessels that are widely used in applications requiring high thermal stability, such as heat exchangers, boilers, and pressure containers in the petroleum industry, among others. Additionally, in the majority of cases, it is necessary to attach A387 to stainless steel in the aforementioned applications. Metal Inert Gas (MIG) welding is a common method of connecting metals in industries. However, process factors such as welding voltage, current rating, as well as the weld bevel angle are critical for achieving a high-quality weld and appropriate mechanical qualities. The purpose of this work is to improve the critical variables of welding, viz., the welding voltage, current rating as well as, the weld bevel angle, in order to get higher impact strength when connecting dissimilar materials, such as A387 steel alloy and SS316 grade stainless steel, by means of Taguchi’s well-known orthogonal array with L9 Arrays. The optimal combination was found to be 140 A welding current, 20 V welding voltage, and 50° angle of bevel for achieving the highest impact strength. Additionally, ANOVA was employed to assess the most influential process variable that has a substantial effect on the weld joint's impact strength. The outcomes demonstrated that the most important variable affecting the welded joint's impact strength was welding current, trailed by welding voltage.