An Investigation on Effect of Welding Current Mode on Weld Quality Characteristics of Microplasma Arc Welding of Inconel 625 Sheets

Abstract

Nickel alloys have gathered wide acceptance in the fabrication of components, which require high temperature resistance and corrosion resistance, such as metal bellows used in expansion joints in aircraft, aerospace and petroleum industry. In case of single-pass welding of thinner sections of this alloy, pulsed current microplasma arc welding was found beneficial due to its advantages over the conventional continuous current process. The paper focuses on studying the effect of continuous current and pulsed current in welding Inconel 625 sheets using microplasma arc welding (PAW) process. Welding was carried out on 0.25 mm thick Inconel 625 sheets using continuous current mode and pulsed current mode separately, keeping all other welding parameters constant. Weld quality characteristics like microstructure, hardness and tensile properties are investigated and it is found that the usage of pulsed current leads to better weld quality characteristics when compared to continuous current mode.