Plasticity and ductile fracture of conventionally manufactured AISI 316L compared to one produced by selective laser melting with and without machining

Abstract The utilization of additively manufactured materials has increased. Knowledge of the behaviour of this prepared material is crucial to designing safe structures and products. However, the properties are different from those of conventionally produced materials. Therefore, the focus is on widely used AISI 316L austenitic stainless steel to present its plasticity and ductile fracture, crucial in decision-making within the design process. The additively manufactured specimens were machined and also left as built, as it is not always economical to machine all the surfaces, which can even be impossible in some cases. However, it has been shown that the machining can be detrimental in some cases. First of all, the stress–strain behaviour was studied in order to simulate all the experiments. Then, several ductile fracture criteria were calibrated using these simulations and mutually compared for three studied material states—conventionally wrought (rolled), as built and machined after printing. The material prepared by the laser powder bed fusion technology exhibited higher yield strength compared to that of the wrought material. The results further show a significant difference when it comes to ductility, which is highest for wrought material and lowest for printed material that was machined. The study also provides information on the mechanisms of hardening and failure with fractography performed to support the findings for widespread austenitic stainless steel.