Sensitivity Analysis of Gas Tungsten Arc Welding Process Variables for Angular Distortion in Chromium Manganese Stainless Steel Using Design Thinking Approach

Abstract

An approach to problem solving that is solution-based is provided by the design methodology known as Design Thinking (DT). To address complicated problems, the five stages of design thinking can be applied. This research article focuses on using the DT method, which includes empathising, defining, and coming up with ideas, to produce high-quality weld joints. The selection of welding process parameters plays a vital role in determining the quality of weld. The weld should be free from weld defects to ensure good performance. One of the major defects that affect the weld quality is angular distortion. During welding the rapid heating and cooling of the work piece results in uneven expansion and contraction in all directions. This results in the work piece getting distorted. It becomes imperative to predict distortion in the work piece so that it can be reduced by providing initial angular distortion in the negative direction. Through empathy, it has been found that the welding process parameters such as welding current (I), welding gun angle (θ), shielding gas flow rate (Q), plate length (L), and welding speed (V), significantly contribute to angular distortion of the weld joint. From the ideation process the following suggestions were arrived to predict angular distortion and identify the factor that has significant effect on angular distortion. A statistical prediction model was developed correlating the welding process parameters with angular distortion. Central Composite Rotatable Design with five factor and five levels was used to develop mathematical models. The experiments were conducted on Chromium Manganese Stainless Steel Grade AISI 202 in GTAW process. Optimization of process parameters was done using Simulated Annealing algorithm. From the sensitivity analysis it was found that the lower values of welding current, welding gun angle and higher values of welding speed, shielding gas flow rate and plate length resulted in minimum angular distortion.