About this Abstract |
| Meeting |
MS&T24: Materials Science & Technology
|
| Symposium
|
Advancements in Steel Structural Refinement
|
| Presentation Title |
Effects of Ferrite/Austenite Ratio in Heterogeneous Nano-Structured Duplex Stainless Steels on Microstructure and Mechanical Properties |
| Author(s) |
Hiromi Miura, Yojiro Oba, Koji Koyama, Masakazu Kobayashi, Chihiro Watanabe |
| On-Site Speaker (Planned) |
Hiromi Miura |
| Abstract Scope |
Duplex stainless steels (DSSs) with different α/γ phase ratios were heavily cold rolled to develop heterogeneous nanostructure [1], in which {001}<011> or {111}<011>α and {011}<112> γ were alternatively stacked. Especially, γ exhibited specific feature that “eye”-shaped twin domains surrounded by shear bans were embedded in low-angle lamellae, while α was simply composed of substructure. The heavily cold-rolled DSSs exhibited large mechanical anisotropy that tensile strength along transverse direction (TD) was larger than that along rolling direction. Tensile tests along TD showed quite high tensile strength (TS) over 1.5 GPa and was further increased with decreasing α/γ ratio. By aging at 748 K, in contrast, TS of the DSSs with higher α/γ ratio was more notably raised up to 2.3 GPa. TEM and EDS analyses suggested that strengthening by aging should be induced by dense precipitation in α and enrichment of elements at α/α , γ/γ and α/γ boundaries |