Corrosion behavior of a dissimilar Inconel 625 superalloy and AISI 316L stainless steel weld

Abstract Corrosion significantly impacts the welding of dissimilar components, leading to a decrease in the lifespan of products. The primary aim of this research is to examine the corrosion behavior of the weld region in dissimilar welding of Inconel 625 and AISI 316L plates with a thickness of 20 mm. The plates are weld together by using continuous current gas tungsten arc welding (CCGTA) and pulsed current gas tungsten arc welding (PCGTAW) methods. The process employs ERNiCr-3, TIG 316L, and a twisted combination of both filler metals (ERNiCr-3+TIG 316L). Specimens with dimensions of 12 mm × 20 mm × 42 mm are obtained by cutting the weld samples for corrosion tests. The divided parts are each submerged in a 100 ml pool of sulfuric acid and are maintained for a combined duration of 240 h. A weight loss investigation is undertaken, in addition to metallurgical characterizations of the specimens. Energy Dispersive Spectroscopy (EDS) in conjunction with Scanning Electron Microscopy (SEM) are utilized to conduct metallurgical investigations. It is observed that twisted filler metal and CCGTA welding method results in the highest amount of mass loss. The least corroded sample is obtained by using twisted filler metal combined with PCGTA welding method.