|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Atom Probe Tomography for Advanced Characterization of Metals, Minerals and Materials
||APT Studies of Cu-Mn-Ni-Si Precipitate Phase Selection for the Wide Range of RPV Steel Compositions Irradiated in UCSB ATR-1 & ATR-2
||Nathan Almirall, Peter Wells, Takuya Yamamoto, David Gragg, Kirk Fields, G. R. Odette, Randy Nanstad, Keith Wilford, Tim Williams
|On-Site Speaker (Planned)
APT characterization studies of Mn-Ni-Si precipitates in irradiated reactor pressure vessel low alloy steels are summarized. The alloy matrix encompasses a wide range of Ni (0.3-3.5%), Mn (0.1-2.0%), Si (0.1-1.2%) and Cu (0.04-0.60%). The UCSB ATR-1 and ATR-2 irradiations from 250 to 320°C were to very high and high fluences, respectively. In the case of low Cu steels, precipitate compositions are close to those for various phases in the Mn-Ni-Si projection of the Fe-Mn-Ni-Si quaternary system. Precipitation of Cu-rich precipitates, enriched in Mn, Ni and Si, with core (Cu)-thin shell (Mn, Ni, Si) structures, form quickly in Cu bearing steels. However, following Cu depletion, a Mn-Ni-Si appendage forms and continues to slowly grow as a separate phase. The emphasis in this talk is on the Mn-Ni-Si phase selection in response to the alloy composition and the corresponding effect on the precipitate characteristics, especially the volume faction.
||Planned: Supplemental Proceedings volume