文章基本信息

标题：Dramatic improvement of strain hardening and ductility to 95% in highly-deformable high-strength duplex lightweight steels
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作者：Seok Su Sohn ; Hyejin Song ; Jai-Hyun Kwak 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2017
卷号：7
期号：1
DOI：10.1038/s41598-017-02183-4
语种：English
出版社：Springer Nature
摘要：Ferrite + austenite duplex lightweight steels have been actively developed by adding low-density Al for overcoming a limitation of stiffness deterioration by a traditional approach to obtain a weight reduction. Multiple-stage deformation mechanism in lightweight steels, i.e., simultaneous formation of deformation-induced martensite and deformation twin and additional plasticity by twinning, has been nominated as an attractive strategy, but shows a steady flow behavior with early plastic instability. Here, we present a newly designed Fe-0.3C-9Mn-5Al steel in order to obtain an optimal level of stability of austenite and a resultant outstanding combination of tensile strength and ductility, e.g., 874 MPa and 72%, together with sufficiently high strain hardening. These enhanced properties are attributed to the decreased austenite stability by controlling the austenite size and alloying partitioning due to variation in austenite fraction inside duplex microstructures. The present work gives a promise for structural applications requiring both reduced specific weight and remarkable deformability.