Comprehensive Investigation of the Mechanical Properties of 316L Stainless Steel Processed via Laser Powder Bed Fusion

The main research objective for the advancement of laser powder bed fusion is the improvement in performance and realization of part quality. The aims of this study were to choose a particular set of process factors and to fully comprehend how they affect the mechanical properties, relative density, microstructure, and surface roughness of a material. The effect of laser power (250 to 350 W), hatch spacing (80 to 100 µm), scanning speed (700 to 1100 mm/s), and energy density on the output responses of 316L stainless steel samples were reported. Heat treatment was performed on the samples at 470 °C for 5 hours, followed by furnace cooling in an argon atmosphere. The microstructures of the samples showed small cells, several types of columnar grains, and network transitions from columnar to cellular at the melt pool boundary. An energy density range of 59 to 80 J/mm 3 was used in this experiment, which revealed a high relative density and good surface quality. The sample hardness increased to 376 HV0.1 at an energy density of 59 J/mm 3 . At an energy density of 51 J/mm 3 , the elongation reached 50%, while an energy density of 81 J/mm 3 produced a high tensile strength of 530 MPa.