Wire and Arc Additive Manufacturing of High Strength Low Alloy Steel: Microstructure and Mechanical Properties

Wire and arc additive manufacturing of high-strength low-alloy steel is performed. The microstructures and mechanical properties of the samples are investigated and correlated with the process heat input. Continuous and pulsed wave welding modes are studied and added material efficiencies are determined. The microstructural characterization and microhardness test reveal that the heat input effect is more impactful when parts are produced with pulsed wave mode. Microstrain evolution and phase fraction are evaluated via synchrotron X-ray diffraction. A higher percentage of austenite in the samples built with higher heat input is determined. Uniaxial tensile testing results show that it is possible to improve ductility and mechanical strength by varying the process parameters.