Microstructure and mechanical properties of large AISI 316 L stainless steel components produced by electron beam powder bed fusion

In this study, AISI 316 L stainless steel sample was fabricated by electron beam powder bed fusion (PBF-EB) additive manufacturing, achieving a build height of 262 mm. The microstructural characteristics and mechanical properties of the tall sample were investigated. Electron backscatter diffraction (EBSD) reveals predominantly columnar crystal structures with significant texture formation along the build direction. The width of the grains reaches up to 165 μm and the height up to 213 μm. Nanoindentation experiments demonstrate anisotropic mechanical properties, with average hardness and elastic modulus varying between 3.41 and 5.07 GPa and 182–232 GPa, respectively. Grain orientation analysis shows that 〈111〉 and 〈101〉 crystallographic directions exhibit higher hardness and elastic modulus compared to 〈001〉 orientation. The research elucidates the complex relationships between microstructural features, crystallographic orientation, and mechanical performance in PBF-EB processed stainless steel, providing insights into material design and process optimization.