Anisotropic Microstructure Evolution in Laser Powder Bed Fusion of 316L Stainless Steel Alloy

Comparative microstructural analysis of the three planes (aligned with the principal axes) of additively manufactured 316 L stainless steel, focusing on anisotropy, is examined. Alloy fabrication utilizes a unique scan rotation angle of 53° and processing parameters recommended by the manufacturer. Variations in porosity content and grain size across the three planes are linked to differences in residual stress resulting from lattice strain. These disparities are attributed to changes in dislocation density and mechanical behavior, primarily governed by the grain boundary strengthening mechanism.