Investigation on the fracture behaviour of wire arc additive manufactured rotor steel weldments after heat treatment

This paper discusses the additive welding of Cr-Mo steel weldment carried out with Cold Metal Transfer Technology (CMT). The mechanical characterization including fracture behaviour and metallography of the Wire Arc Additive Manufacture (WAAM) weldments in the As Welded (AW) and Post Weld Heat Treated (PWHT) conditions were investigated. The longitudinal and transverse orientations parallel to building and deposition directions respectively were found to influence the fracture behavior of weldments. The specimens of longitudinal direction showed lower toughness and tensile strength when compared to the specimens of transverse direction both in the case of AW and PWHT weldments. Orientation was also observed to influence the elastic-plastic fracture toughness (J integral) values both in the as welded and heat-treated specimens. Fracture topographical analysis of specimens carried out by Scanning Electron Microscope (SEM) in association with Energy Dispersive Spectroscopy (EDS) showed the presence of soft ductile features and Mn deposition respectively in the specimens of transverse direction and justified the findings.