Interpass temperature effects on the corrosion performance of WAAM ER316L stainless steel multi-layer walls using a potentiostatic pulse test

Abstract The effect of interpass temperature on the microstructure and pit nucleation behaviour in wire and arc additive manufacturing (WAAM) deposited ER316L stainless steel was investigated. Lowering the interpass temperature increased the ferrite content and decreased the sigma phase precipitation. Potentiostatic pulse measurements showed that the WAAM ER316L pits developed predominantly near sigma phases and had higher pit density compared to a wrought 316L (UNS S31600). The pitting susceptibility of WAAM ER316L increases with increasing interpass temperature due to the precipitation of larger sigma phase enhancing the elemental segregation.