About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
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Thermodynamics and Kinetics of Alloys
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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 |