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Advanced microstructural analyses of materials degradation and atomic transport in extreme environments


EMSL Project ID
47700

Abstract

Environmental degradation is a major problem in high-temperature water environments such as those found in nuclear reactors and other forms of steam generator and high-temperature turbine environments. Despite several decades of research, there is no definitive answer as to the exact mechanisms by which these materials corrode and oftentimes crack. Recently we have shown that site-specific microstructural analyses can be performed on corroded and oxidized surfaces, grain boundaries and crack tips using transmission electron microscopy and atom-probe tomography. We have developed novel focused-ion beam sample preparation techniques that enable highly-site-specific specimens (target volume ~100×100x100 nm3) to be prepared reliably for both analytical techniques. Here we propose to use these newly developed FIB, TEM and APT techniques to study the environmental degradation and cracking phenomena of both commercial alloys and model high-purity binary alloys exposed to high-temperature, high-pressure corrosive water environments. These studies will result in new microstructural insights into the role of atomic diffusion and the mechanistic origins of environmental degradation and stress-corrosion cracking of materials critical to both current and next-generation nuclear reactor components and other extreme environments. We will also continue to develop directly correlated TEM/APT studies and new FIB-based sample preparation methods within this proposal, and pursue cross-correlative analyses using TEM and APT.

Project Details

Start Date
2012-12-01
End Date
2013-11-07
Status
Closed

Team

Principal Investigator

Daniel Schreiber
Institution
Pacific Northwest National Laboratory

Team Members

Karen Kruska
Institution
Pacific Northwest National Laboratory

Matthew Olszta
Institution
Pacific Northwest National Laboratory

Alicia Certain
Institution
Pacific Northwest National Laboratory

Larry Thomas
Institution
Pacific Northwest National Laboratory

Bruce Arey
Institution
Pacific Northwest National Laboratory

Stephen Bruemmer
Institution
Pacific Northwest National Laboratory

Related Publications

D. K. Schreiber, M. J. Olszta, L. E. Thomas and S. M. Bruemmer, ?Grain Boundary Characterization of Alloy 600 Prior To and After Corrosion by Atom Probe Tomography and Transmission Electron Microscopy,? Proc. 16th Int. Conf. Environmental Degradation of Materials in Nuclear Power Systems ? Water Reactors,? NACE International, 2013, in press.
M. J. Olszta, D. K. Schreiber, M. B. Toloczko and S. M. Bruemmer, ?Alloy 690 Surface Nanostructures During Exposure to PWR Primary Water and Potential Influence on Stress Corrosion Crack Initiation,? Proc. 16th Int. Conf. Environmental Degradation of Materials in Nuclear Power Systems ? Water Reactors,? NACE International, 2013, in press.
Olszta MJ, DK Schreiber, LE Thomas, and SM Bruemmer. 2012. "High-Resolution Crack Imaging Reveals Degradation Processes in Nuclear Reactor Structural Materials." Advanced Materials & Processes 170(4):17-21.
Schreiber DK, MJ Olszta, and SM Bruemmer. 2013. "Directly correlated transmission electron microscopy and atom probe tomography of grain boundary oxidation in a Ni-Al binary alloy exposed to high-temperature water." Scripta Materialia 69(7):509-512. doi:10.1016/j.scriptamat.2013.06.008
Schreiber DK, MJ Olszta, and SM Bruemmer. 2014. "Grain boundary depletion and migration during selective oxidation of Cr in a Ni-5Cr binary alloy exposed to high-temperature hydrogenated water." PNNL-SA-102624, Pacific Northwest National Laboratory, Richland, WA. [Unpublished]
Schreiber DK, MJ Olszta, DW Saxey, K Kruska, KL Moore, S Lozano-Perez, and SM Bruemmer. 2013. "Examinations of Oxidation and Sulfidation of Grain Boundaries in Alloy 600 Exposed to Simulated Pressurized Water Reactor Primary Water." Microscopy and Microanalysis 19(3):676-687. doi:10.1017/S1431927613000421
Wang CM, A Genc, H Cheng, L Pullan, DR Baer, and SM Bruemmer. 2014. "In-Situ TEM Visualization Of Vacancy Injection And Chemical Partition During Oxidation Of Ni-Cr Nanoparticles." Scientific Reports 4(3683):1-6. doi:10.1038/srep03683