High Cycle Fatigue Behavior of TIG Welded Joint at Optimum Parametric Condition

In this study, AISI 316L stainless steel plates are joined together in a square butt joint arrangement using a semiautomatic tungsten inert gas (TIG) welding process. The research project has two goals in mind. To create mathematical models based on the recorded data, a series of experiments are first carried out using the Box-Behnken design of response surface methodology (RSM). Next, desirability function analysis (DFA) is used to perform multi-objective optimisation for a subset of responses at once. Secondly, a set of another TIG welded joints are prepared at the obtained optimum parametric condition and then high cycle fatigue behaviour of the welded joints as well as base metals are investigated at room temperature with a stress ratio R = 0.1. Furthermore, the fracture surfaces of the fatigued specimens are analysed by scanning electron microscopy (SEM). The result shows that welded joint depicts almost 8% higher fatigue limit compare to base metal.