| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Steels in Extreme Environments
|
| Presentation Title |
CHARACTERIZATION OF PRECIPITATION-STRENGTHENING HEAT-RESISTANT AUSTENITIC STAINLESS STEELS WITH MINOR ALLOYING ADDITIONS |
| Author(s) |
Qing-Qiang Ren, Yajie Zhao, Rishi Pillai, Jonathan Poplawsky, Yukinori Yamamoto, Martin Detrois, Paul Jablonski |
| On-Site Speaker (Planned) |
Qing-Qiang Ren |
| Abstract Scope |
The role of minor alloying additions in 347H stainless steels (UNS34709, ASTM A240/240M) on the creep-rupture properties at 650-750°C, and the microstructure evolution during isothermal exposure at 750°C will be discussed. The precipitation kinetics of strengthening and deteriorating secondary phase precipitates will be the main focus. Four different 347H heats containing various amounts of boron and nitrogen additions were prepared and evaluated. Microstructural characterization show that the primary and secondary precipitates are the same among all four steels: MC (M: mainly Nb) and M23C6 (M: mainly Cr) carbides, and σ-phase. The combined additions of B and N were found to stabilize the strengthening M23C6 carbides by retarding their transition to the detrimental σ- phase during thermal exposure. The observed precipitate kinetics explains the improvement of creep-rupture properties of 347H stainless steels with B and N additions. Research is sponsored by US DOE, Office of Fossil Energy and Carbon Management. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Iron and Steel, High-Temperature Materials, |