About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
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| Symposium
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Advanced Real Time Imaging for Materials Science and Processing
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| Presentation Title |
Time-resolved X-ray Diffractometry of Grain Coarsening after a Massive-like Ferrite–Austenite Transformation Following Solidification in Fe–0.45C Steels |
| Author(s) |
Yanxin Wang, Masahiro Ohsaki, Taka Narumi, Ryoji Katsube, Hideyuki Yasuda |
| On-Site Speaker (Planned) |
Hideyuki Yasuda |
| Abstract Scope |
Although coarse austenite (FCC) grains are often observed in the as-cast microstructure of carbon steels, the timing and mechanism of their coarsening during cooling remain unclear. In our previous work, we demonstrated that fine austenite grains formed through a massive-like ferrite (BCC)–austenite transformation rapidly coarsen immediately after the transformation, as revealed by synchrotron radiation X-ray imaging. Recently, we developed a time-resolved X-ray diffractometry technique using a tomography setup (4D-CT+XRD) to investigate crystallographic orientation distributions during coarsening. Rod-shaped specimens (diameter: 0.8 mm) of Fe–0.45C–0.6Mn–0.3Si alloys (in mass%) were melted and subsequently cooled at 20 K/min under vacuum. Upon detecting the massive-like transformation, the temperature was held constant, and XRD patterns were captured using the 4D-CT+XRD system. The grain number index, estimated from the orientation distributions, clearly showed a reduction to half within 20 seconds after the transformation. We will discuss the coarsening mechanism based on these direct observations. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Solidification, Phase Transformations, |