Microstructure, Mechanical Properties and Cross-sectional Behaviour of Additively Manufactured Stainless Steel Cylindrical Shells

Abstract

<p>Powder bed fusion (PBF) is an additive manufacturing method that enables complex metallic components to be manufactured with high precision. The microstructure, mechanical properties and cross-sectional behaviour of PBF additively manufactured stainless steel circular hollow sections are investigated through experiments in this paper, with a view to applications in construction. The experimental programme included tensile coupon tests, microstructural characterisation, initial geometric imperfection measurements and compression tests on PBF 316L stainless steel cylindrical shells with large diameter-to-thickness (<em>D</em>/<em>t</em>) ratios. Advanced measurement methods – 3D laser scanning and digital image correlation, were employed to measure the specimen geometries prior to testing and deformation fields during testing, respectively. The possible anisotropy in mechanical properties was examined through tensile coupon tests and correlated with the underlying microstructural and textural features. Compression tests were performed to investigate the resistance against local buckling of thin-walled cylindrical shells produced by PBF. All cylindrical shells buckled below their yield loads with a chequerboard failure mode and revealed the anticipated trend of reducing capacity relative to the yield load with increasing local slenderness, reflecting the increasing susceptibility to local buckling.</p>