About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
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| Symposium
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Characterization of Minerals, Metals and Materials 2026 - In-Situ Characterization Techniques
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| Presentation Title |
Carbide-Mediated Austenite Formation and TRIP Activation in Medium-Mn Steel: An In-Situ Synchrotron X-Ray Study |
| Author(s) |
Roohallah Surki Aliabad, Pentti Karjalainen, Saeed Sadeghpour, Ehsan Ghassemali, Jukka Kömi, Vahid Javaheri |
| On-Site Speaker (Planned) |
Roohallah Surki Aliabad |
| Abstract Scope |
Two routes for carbide-assisted austenite formation were studied in a medium-Mn steel. The initial hot-rolled martensitic microstructure contained 7% retained austenite (RA). In the first route, slow (1°C/s) heating to 680 °C led to carbide precipitation in martensite and partial pearlitic transformation of RA. During 10 min soaking, new austenite formed, resulting in about 34% of RA. In the second route, the route-one microstructure was cold rolled to 50% reduction, causing partial strain-induced martensitic transformation and high dislocation density in RA. Upon slow reheating and 10 min soaking at 680 °C, RA decomposed into fine carbides, which promoted the formation of new austenite, yielding ≈35% of RA. In-situ high-energy X-ray diffraction, electron microscopies, and Thermo-Calc/DICTRA modeling revealed the kinetics of carbide-assisted austenite formation with different morphologies. Using quasi-in-situ tensile testing coupled with electron backscatter diffraction, different deformation mechanisms, strain partitioning, and discontinuous yielding were identified, linking microstructural evolution to mechanical response. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Mechanical Properties, Iron and Steel, Characterization |