Tungsten inert gas (TIG) welding is a multi-input and multi-output variant process. The input process parameters and other factors of welding process interact in a complicated manner and influence the weld quality – directly or indirectly. Keeping this in mind, the present work has been planned to study the impact behaviour of TIG weldment through experiments, analysis and optimization. Experimental runs have been considered as per Box-Behnken design of response surface methodology (RSM). Based on the recorded data, the mathematical models have been developed to study the effect of process parameters on impact strength. ANOVA has been utilized to identify the influence of input process parameters on the response i.e. impact strength. RSM and cuckoo search optimization (CSO) algorithm have also been applied to optimize the impact strength.
Weld quality mainly depends on the weld bead geometry and mechanical-metallurgical characteristics of the welded joint which has a direct relationship with the type of welding process being used and its input process parameters i.e. welding current, arc voltage, travel speed etc. In the present study, determination of tungsten inert gas (TIG) welding input parameters for achieving maximum tensile strength of 316L austenitic stainless steel is investigated. Box-Behnken design of response surface methodology has been employed to formulate the experimental plan to identify the effect of process parameters on tensile strength. Square butt joint configuration has been made using three factors - three levels of welding input parameters. Joint strength has been evaluated by notch tensile strength (NTS) and Unnotch tensile strength (UTS) method and correlated with microstructure and micro hardness of the weld. The results indicate that gas flow rate has greater influence on both NTS and UTS followed by welding current.