Optimization of weldment in bead on plate welding of nickel based superalloy using Activated flux tungsten inert gas welding (A-TIG)

Abstract

The main objective of this research article is to identify the optimized welding process parameters for a 6.5 mm thick Inconel 625 nickel based superalloy by Activated flux tungsten inert gas welding (A-TIG). The bead on trial experiments was carried out on a L25 orthogonal array with preferable input responses like current, torch speed and arc gap. Output responses considered were welding heat input and heat affected zone width (HAZ). Multi criteria decision making optimization tool, Grey relational analysis (GRA) was used to find the optimum condition. Analysis of variance (ANOVA) was employed to determine the consequence of each individual input’s response. From various experimental trials 300 Amps current, 75 mm/min torch speed and 1 mm arc gap with a heat input of 4.212 kJ/mm were found to be optimal input responses. The optimized sample was examined by Optical microscopy for a detailed study of the interdendritic region of the HAZ and weld zone.