Low cycle fatigue behavior of wire arc additive manufactured and solution annealed 308 L stainless steel

Abstract

Wire arc additive manufacturing (WAAM) has attracted much attention for many industrial fields owing to its high productivity and flexibility. However, little is known about the fatigue behavior of WAAM austenitic stainless steel (SS). In this study, microstructural characterization, quasi-static tensile tests, and strain controlled low cycle fatigue tests were carried out on a 308 L SS fabricated by WAAM and solution annealing. Hot-rolled 308 L SS was also studied as a reference material. The quasi-static tensile properties, cyclic deformation behaviors, fatigue lives and fatigue failure mechanisms are comparably investigated and found to be dependent on their distinct microstructures. Compared with the hot-rolled counterparts, the WAAM specimens showed slightly longer fatigue life at relatively high strain amplitudes, but shorter fatigue life at low strain amplitudes, which is attributed to their worse crack initiation, but better crack propagation resistance.