|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Hume-Rothery Award Symposium: Alloy Phase Chemistry at the Atomic Level - Opportunities and Challenges
||Advanced Microstructural and Chemical Characterization of Nano-scale NiMnSi Precipitates Formed in Irradiated Reactor Pressure Vessel Steels Using Atom Probe Tomography and Scanning Transmission Electron Microscopy
||Philip Edmondson, Chad Parish, Randy Nanstad
|On-Site Speaker (Planned)
Reactor pressure vessels (RPV) used in light-water nuclear reactors are typically constructed from low-alloy steels. Under high-fluence irradiation, second phases rich in Ni, Mn and Si are observed to form. These NiMnSi-rich precipitates are known to degrade the mechanical properties of the RPV steel. Atom probe tomography (APT) has typically been applied to the investigation of these precipitates, but accurate quantification of precipitate chemistry is difficult to obtain due to trajectory aberrations. APT along with Scanning Transmission Electron Microscopy with X-ray spectroscopy and advanced data mining techniques have been used to characterize a RPV steel irradiated during service at a nuclear power plant. The experimental results, combined with modeling of the X-ray data, provide unique insight into the chemistry of the NiMnSi precipitates. These results will be discussed in terms of the role of precipitate chemistry on second phase formation, and the use of correlative microscopy methods in nano-scale characterization.
||Planned: Supplemental Proceedings volume