Strength–ductility synergy in 316L austenitic stainless steel with a heterogeneous structure

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 2022-12, Vol.861, p.144385, Article 144385
• Main Authors: Li, Zhengning, Jiang, Yang, La, Peiqing, Kang, Jilong, Wei, Fuan
• Format: Article
• Language: English
• Subjects: Austenitic stainless steel; Cold rolling; Heterogeneous structure; Mechanical properties; Reversion
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2022.144385

316L austenitic stainless steel (ASS) with a heterogenous structure (HS) and excellent strength–ductility synergy was fabricated by combining cold rolling (CR) with subsequent annealing. The micro-nano grain size distribution of casting microstructure provided a favorable conditions for the preparation of HS. The HS is characterized by trimodal grain size distribution of austenite, residual strain-induced α′-martensite, and annealing twins. The fine-grain strengthening and back stress hardening play a major role in HS 316L ASS strengthening. Moreover, the favorable ductility was primarily attributed to heterogeneous deformation-induced (HDI) strain hardening of soft/hard interfaces in the HS. When the rolled steel with 70% deformation was annealed at 600 °C for 1 h, the yield strength (YS) of 1183 MPa with a total elongation (TEL) of 13% was obtained. •A heterogeneous structure (HS) 316L ASS was fabricated.•The HS 316L ASS obtained an outstanding strength-plasticity synergy.•Microstructure-tensile property correlation in HS 316L ASS was established.