Supreme tensile properties in precipitation-hardened 316L stainless steel fabricated through powder cold-consolidation and annealing

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 893; p. 146107
• Main Authors: Lee, Do Won, Asghari-Rad, Peyman, Heo, Yoon-Uk, Son, Sujung, Park, Hyojin, Lee, Ji-Su, Jang, Jae-il, Lee, Byeong-Joo, Kim, Hyoung Seop
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2024
• Subjects: Cold-consolidation; Grain refinement; High-pressure torsion; Powder metallurgy; Sigma phase precipitation; Cold-consolidation; Sigma phase precipitation; Powder metallurgy; Grain refinement; High-pressure torsion
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2024.146107

One of the key goals of processing 316L stainless steel by powder metallurgy (PM) techniques is to achieve industrial-viable tensile properties without structural defects like poor densification, undesired phase transitions, and oxidation during high-temperature sintering. To address this, this study adopts high-pressure torsion to fabricate a fully dense structure at ambient temperature through cold consolidation. The samples fabricated by the present PM-based technique exhibits considerably enhanced tensile properties compared to counterparts processed by conventional PM techniques, with a remarkable yield strength of 1 GPa and total elongation of 46%. Additionally, the segregation of certain elements during subsequent annealing results in a unique microstructure with nano-scale sigma precipitates which induces dislocation pile-up, leading to improved yield strength and retarded dislocation motion. The results indicate that the present PM-based route is an applicable technique to achieve the strength-ductility synergy in 316L stainless steel.