On collapse of 3D printed thin-walled PBF-LB/M 316L stainless steels under inelastic stress cycling

• Published in: Thin-walled structures Vol. 215; p. 113413
• Main Authors: Yadegari, M.J., Zeinoddini, M., Ezzati, M., Kashani-Bozorg, S.F., Miresmaeili, R., Ghafoori, E.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2025
• Subjects: Additive manufacturing; Cyclic plasticity; Deformation-induced martensite; Laser powder bed fusion; Ratcheting; Stainless steel 316L; Laser powder bed fusion; Ratcheting; Additive manufacturing; Stainless steel 316L; Deformation-induced martensite; Cyclic plasticity
• ISSN: 0263-8231
• DOI: 10.1016/j.tws.2025.113413

•Cyclic plastic failure of additively manufactured (AM) thin-walled SS-316L is studied.•AM samples show brittle ratcheting failure, whereas wrought ones are notably ductile.•AM samples endured a markedly lower number of cycles to failure, than wrought ones.•AM SS-316L samples show lower deformation-induced martensite rates than wrought ones. Laser-based powder bed fusion of metals (PBF-LB/M) has emerged as a leading Additive Manufacturing (AM) technique, offering exceptional capabilities for near-net-shape fabrication of complex thin-walled structures. This technology finds promising applications in aerospace, biomedical, and energy sectors, where lightweight components with intricate geometries are essential. Despite its advantages, PBF-LB/M is characterised by sensitivity to process parameters and anisotropic mechanical properties, necessitating a comprehensive understanding of its behaviour under operational conditions. This study addresses the relatively unexplored topic of cyclic plasticity in thin-walled components manufactured via PBF-LB/M, with a particular focus on strain ratcheting collapse in SS-316L steel. Thin-walled specimens, produced using both PBF-LB/M and conventional manufacturing methods, were subjected to inelastic uniaxial stress cycling. The results revealed that the PBF-LB/M specimens experienced ratcheting failure in approximately 50% of the cycles when compared to their conventionally manufactured counterparts. Furthermore, the failure modes varied between the two groups: the PBF-LB/M specimens primarily demonstrated brittle failure, whereas the conventionally fabricated specimens exhibited ductile failure mechanisms. Microstructural analysis revealed that PBF-LB/M specimens retained a single-phase austenitic structure at moderate ratcheting strain. However, at high ratcheting strain, around 75% of the material experienced a transformation into a martensitic phase. These findings underscore the shortcomings of PBF-LB/M-fabricated SS-316L steel under inelastic cyclic loading applications, highlighting the need for optimised design and processing strategies to enhance the cyclic performance and reliability of thin-walled components produced via AM technologies.