Wire arc additive manufactured AWS ER100S-G steel: Very high cycle fatigue characterization

This paper presents a comprehensive study on the very high cycle fatigue (VHCF) characterization of a wire arc additive manufactured (WAAM) AWS ER100S-G steel. The demand for highperformance materials with superior fatigue properties has grown exponentially. However, the VHCF behavior of large-format WAAM'd structures remains relatively unexplored. In this study, a series of VHCF tests were conducted under fully reversed cyclic loading conditions to investigate the extended fatigue life (performance) of the WAAM ER100S-G steel. The VHCF properties, relative to conventional fatigue employing a servohydraulic testing system, of the WAAM ER100S-G steel were evaluated by analyzing the stress-life (S-N) curves, fatigue crack initiation, and propagation behavior, in a statistical framework, and the fracture surfaces. The results revealed the controlling mechanisms of VHCF failure of the WAAM ER100S-G steel and the fatigue response of the material beyond the conventional fatigue limit of 107 cycles. The findings provide valuable insights into the influence of WAAM-induced defects/microstructure on the extended fatigue performance of WAAM ER100S-G steel, which can aid in optimizing fatigue and durability design guidelines for additive manufacturing applications in high-cycle and very highcycle fatigue domains.