About this Abstract |
Meeting |
2020 TMS Annual Meeting & Exhibition
|
Symposium
|
Radiation Effects in Metals and Ceramics
|
Presentation Title |
Dose Rate and Temperature Effect on the Stability of Alpha Prime Precipitates in Ultra-high Purity Fe-Cr Alloys |
Author(s) |
Yajie Zhao, Arunodaya Bhattacharya, Philip D. Edmondson, Caleb P. Massey, Jean Henry, Steven J. Zinkle |
On-Site Speaker (Planned) |
Yajie Zhao |
Abstract Scope |
Cr-rich alpha prime (α’) precipitates are detrimental to the mechanical properties of FeCr based ferritic-martensitic steels. Understanding α’ precipitation under irradiation conditions is essential for application of this steel in nuclear reactor environments. To study the effect of dose rate (ballistic dissolution) and irradiation temperature (radiation-enhanced diffusion) on α’ formation, ultra-high purity Fe-Cr alloys with 12-18 wt.% Cr (in either solid solution or thermally aged to form pre-existing α’precipitates) were irradiated with 8 MeV Fe ions to a midrange (~1 um) dose of 0.35-3.5 displacements per atom (dpa) between 300-450 °C at 10^-3, 10^-4 and 10^-5 dpa/s. Following irradiation, atom probe tomography (APT) was employed to characterize the number density, radius and Cr concentration of Cr-rich clusters. Homogeneously distributed α’ precipitates were revealed when radiation-enhanced diffusion dominates over ballistic dissolution (>350°C). The segregation of Cr, C and N atoms to dislocation loops was also observed. |
Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |