Influence of parameters on mechanical and micro-structural properties of tungsten inert gas (TIG) welded joint of 1 mm thin Inconel 625 plates

Abstract

Inconel 625 (IN625), since its invention, has been a material of choice for industries where components in service conditions are exposed to extremely high temperatures, corrosion, and oxidation environments. As per the American welding society for butt-joining such alloys in sheets, non-traditional techniques are the best means for producing permanent joints. These techniques require high-cost setup and high maintenance costs which are only economical for high-volume assembly line fabrication in mass-production facilities. Therefore, Tungsten Inert Gas (TIG) welding is highly suitable for producing defect-free autogenous weldments in high-strength alloy sheets with a thickness below 3mm. The current work focuses on the experimental investigation of the TIG welding of Inconel 1mm sheets. In this work, mechanical properties and microstructure are studied for controlled heat input of TIG welding. Current is varied from 40A to 65A and voltage from 10V to 12V. Only three combinations of parameters show sound weld visually and are analyzed by performing various testing. The main objective of the study is to find the feasible process parameters for the micro joining of IN625 sheets. From this discussion, it appears that arc energy, welding current, and voltage significantly affect the quality of the weld.