| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Mechanical Response of Materials Investigated Through Novel In-Situ Experiments and Modeling
|
| Presentation Title |
Exploring unusual Lüders deformation in UFG high-Mn austenitic steel |
| Author(s) |
Sukyoung Hwang, Hirokazu Kato, Kazuho Okada, Myeong-Heom Park, Nobuhiro Tsuji |
| On-Site Speaker (Planned) |
Sukyoung Hwang |
| Abstract Scope |
Ultrafine-grained (UFG) high-Mn austenitic steel exhibited unusual discontinuous yielding on its stress-strain curve, characterized by a yield drop followed by a stress plateau indicating Lüders deformation. Utilizing the digital image correlation (DIC) technique, a strain-localized region known as a Lüders band was observed to propagate during Lüders deformation. In-situ synchrotron XRD measurements during the tensile test revealed that as the Lüders band front passed through the XRD beam position, dislocation density increased significantly, approximately 300 times, while stacking faults increased slightly. Deformation twins were observed using STEM and SEM-ECCI, relative to the position of the Lüders band. The strain induced by twinning was theoretically estimated based on the experimental findings, revealing its contribution to macroscopic Lüders strain to be only 2.3%. All results obtained consistently demonstrated that Lüders deformation in the high-Mn austenitic steel was predominantly given by dislocations rather than twinning. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Iron and Steel, Characterization, Mechanical Properties |