About this Abstract |
| Meeting |
MS&T26: Materials Science & Technology
|
| Symposium
|
Advanced Materials for Harsh Environments
|
| Presentation Title |
Grain Size Effects on Microstructural Evolution and Mechanical Properties of Neutron Irradiated Grade 91 Ferritic/Martensitic Steel |
| Author(s) |
Xingshuo Zhang, Anish Ranjan, Joshua Rittenhouse, Sohail Shah, Mukesh Bachhav, Haiming Wen |
| On-Site Speaker (Planned) |
Xingshuo Zhang |
| Abstract Scope |
Ferritic–martensitic steels are key structural materials for advanced nuclear systems, yet their irradiation response strongly depends on grain size and remains insufficiently understood. This study systematically investigates the effects of grain size on irradiation-induced microstructural and mechanical evolution in Grade 91 (Fe-9Cr-1Mo) ferritic/martensitic steel, including coarse-grained, ultrafine-grained, and nanocrystalline variants. Neutron irradiation is conducted at 300 °C and 500 °C to doses of 2 and 6 displacements per atom (dpa). Tensile testing is performed to quantify changes in yield strength and plasticity. Transmission electron microscopy (TEM) combined with energy-dispersive X-ray spectroscopy is used to characterize irradiation-induced defects, such as dislocation loops and secondary phases, and to obtain quantitative microstructural information. Atom probe tomography (APT) is further employed to analyze precipitation and solute segregation. By correlating mechanical properties with microstructural evolution, this work provides mechanistic insights into irradiation behavior and offers guidance for the design of radiation-resistant G91 steel. |