Corrosion behaviour study of Inconel 617 TIG and A-TIG weldments using potentiodynamic polarisation test and intergranular corrosion test

Abstract

Inconel 617 alloy is known for its impressive resistance to numerous corrosive environments and is widely used in high-temperature applications. This study analyses the microstructure and corrosion behaviour of the Inconel 617 weldments fabricated by activated flux tungsten inert gas (A-TIG) welding and TIG welding. Potentiodynamic polarisation (PDP) test in a 3.5% NaCl solution and intergranular corrosion (IGC) test was conducted to analyse the corrosion behaviour of the base metal (BM) and weldments. In accordance with the PDP test evaluation, the BM, TIG weld and A-TIG weld samples had corrosion rates of 0.0028, 0.0156 and 0.0043 mpy, respectively. PDP test results showed that all three samples had outstanding corrosion resistance. According to IGC test findings, the A-TIG weld sample had a greater corrosion resistance of 15.1 mpy when compared to BM and the TIG weld sample, which had corrosion resistances of 19.78 and 23.2 mpy, respectively. Chromium depletion at the grain boundaries caused by carbide formation was the reason for the TIG weld sample's poor corrosion resistance.