TY - JOUR
T1 - Transmission electron microscopy of oxide development on 9Cr ODS steel in supercritical water
AU - Siwy, A. D.
AU - Clark, T. E.
AU - Motta, A. T.
N1 - Funding Information:
This research was supported by a DOE NERI Grant No. DE-FC07-06ID14744. The authors thank JAEA for providing the 9Cr ODS steel and Todd Allen, Yun Chen, and co-workers at the University of Wisconsin-Madison for supplying the corrosion samples used in this study. The authors also thank Joe Kulik and Josh Maier at the Materials Research Institute, Pennsylvania State University for help in TEM sample preparation and examination, and Jeremy Bischoff and Jamie Kunkle for helpful discussions. This publication was supported by the Pennsylvania State University Materials Research Institute NanoFabrication Network and the National Science Foundation Cooperative Agreement No. 0335765, National Nanotechnology Infrastructure Network, with Cornell University.
PY - 2009/7/15
Y1 - 2009/7/15
N2 - Oxide layers formed on 9Cr oxide dispersion strengthened ferritic steel alloys during exposure to 600 °C supercritical water for 2- and 4-weeks were examined using cross-sectional transmission electron microscopy. A focused ion beam in situ lift-out technique was used to produce site-specific samples with electron transparent areas up to 8 μm by 10 μm. The oxide layers consist of several sub-layers: an Fe-rich outer oxide, a Cr-rich inner oxide, and a diffusion layer, extending beyond the oxide front into the metal. An evolution of the oxide layer structure is seen between 2 and 4 weeks, resulting in the development of a band of Cr2O3 at the diffusion layer/metal interface from the previously existing continuous mixture of FeCr2O4 'fingers' and bcc metal. It is believed that transport in this Cr2O3 layer at the diffusion layer/metal interface becomes the rate-limiting step for oxide advancement, since this change in oxide structure also corresponds to a decrease in corrosion rate.
AB - Oxide layers formed on 9Cr oxide dispersion strengthened ferritic steel alloys during exposure to 600 °C supercritical water for 2- and 4-weeks were examined using cross-sectional transmission electron microscopy. A focused ion beam in situ lift-out technique was used to produce site-specific samples with electron transparent areas up to 8 μm by 10 μm. The oxide layers consist of several sub-layers: an Fe-rich outer oxide, a Cr-rich inner oxide, and a diffusion layer, extending beyond the oxide front into the metal. An evolution of the oxide layer structure is seen between 2 and 4 weeks, resulting in the development of a band of Cr2O3 at the diffusion layer/metal interface from the previously existing continuous mixture of FeCr2O4 'fingers' and bcc metal. It is believed that transport in this Cr2O3 layer at the diffusion layer/metal interface becomes the rate-limiting step for oxide advancement, since this change in oxide structure also corresponds to a decrease in corrosion rate.
UR - http://www.scopus.com/inward/record.url?scp=67349115278&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=67349115278&partnerID=8YFLogxK
U2 - 10.1016/j.jnucmat.2009.03.032
DO - 10.1016/j.jnucmat.2009.03.032
M3 - Article
AN - SCOPUS:67349115278
SN - 0022-3115
VL - 392
SP - 280
EP - 285
JO - Journal of Nuclear Materials
JF - Journal of Nuclear Materials
IS - 2
ER -