About this Abstract |
| Meeting |
2023 TMS Annual Meeting & Exhibition
|
| Symposium
|
Thermodynamics and Kinetics of Alloys
|
| Presentation Title |
Effect of N and/or B Additions on the Precipitation Kinetics in Isothermally Aged and Creep Ruptured 347H Stainless Steels |
| Author(s) |
Qing-Qiang Ren, Yukinori Yamamoto, Michael Brady, Jonathan Poplawsky, Martin Detrois, Paul Jablonski, Jeffrey Hawk |
| On-Site Speaker (Planned) |
Qing-Qiang Ren |
| Abstract Scope |
Precipitation kinetics of three 347H stainless steels (UNS-S34709) with changes in the N (22-168 wppm) and B (<5 and 11 wppm) contents were experimentally evaluated through microstructure characterization by electron microscopy and atom probe tomography after isothermal aging at 750 °C and creep-rupture testing at 600-750 °C. The obtained precipitation behavior was used to support modeling-and-simulation activities for material life assessment under the on-going eXtremeMAT (XMAT) program funded by the US-Department of Energy, Office of Fossil Energy and Carbon Management. Strengthening metastable M23C6 carbides formed in the early stage of isothermal aging are replaced by sigma phases after prolonged exposure. B additions significantly improved the M23C6 stability relative to the sigma phase, while N additions did not. Creep deformation, on the other hand, accelerated the transition from M23C6 to sigma. The transition mechanism will be discussed with the analyzed composition and precipitate stability. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Characterization, Iron and Steel, Phase Transformations |