| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Meeting Materials Challenges for the Future of Fusion Energy
|
| Presentation Title |
Design Strategy of PWHT-Free Reduced-Activation Bainitic Steel for Vacuum Vessel Components in Fusion Reactors |
| Author(s) |
Yukinori Yamamoto, Tim Graening Seibert, Roger Miller |
| On-Site Speaker (Planned) |
Yukinori Yamamoto |
| Abstract Scope |
Bainitic steels with reduced-activation alloy design are beneficial for fusion reactor vacuum vessels and structural rings to address high volume recycling and/or disposal considerations of large-scale structural components. Low Cr containing Cr-W bainitic ferritic steels, based on Fe-3Cr-3W-0.2V-0.1Ta-0.1C (3Cr-3WVTa steel), were proposed in 1990’s which met these property requirements. The present study introduces a new alloy design strategy of bainitic steels eliminating a requirement of post-weld heat treatment (PWHT) by considering large-scale component production while satisfying multiple demands of mechanical properties. The design strategy includes (1) increased hardenability to maintain the strength, while (2) lowering the hardness to reduce the property variation across the weldment. A compositional modification of 3Cr-3WVTa steel based on thermodynamic calculation and experimental validation proves that an alloy with increased Mn and reduced C can meet the property requirement without PWHT, suggesting the feasibility of the design strategy. The detailed alloy modification story will be discussed. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Iron and Steel, Phase Transformations, Joining |