Interpass temperature effects on WAAM ER316L stainless steel corrosion using potentiostatic pulse tests

Abstract

The effect of interpass temperature on the microstructure and pit nucleation behaviour in wire and arc additive manufacturing (WAAM) deposited ER316L stainless steel is investigated. Lowering the interpass temperature increases the ferrite content and decreases the sigma phase precipitation. Potentiostatic pulse measurements show that the WAAM ER316L pits develop predominantly near sigma phases and have 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.