XPS Characterization of the passive film/corrosion products formed on Carbon steel and Ni-base alloy in YM repository Environment
EMSL Project ID
3380
Abstract
We are performing research on Corrosion Behavior of Rock Bolt Carbon Steels and Ni-base alloys for the Yucca Mountain (YM) project. We found some interesting corrosion behavior of the above rock bolt steels in the simulated repository environment at different temperatures. Since the repository environment contains different ions such as Bicarbonate, Chloride, Sulfates, Silicates etc.. these ions influences the corrosion behavior of steels depending on the temperature. Hence we are interested to identify the type of corrosion products and also the chemistry of such product layers and also the thickness. This we would like to analyze by depth profiling the layers by ion etching method. These results would help us to support the electrochemical and microscopy results as there was difference in corrosion rates and also the corrosion morphology. Similary we did some initial study on the Ni-base alloy C-22 in chloride environment and the polarization results show that its shows typical active passive behavior in neutral pH-7. At acidic pH (3), additional oxidation peak was seen. Our impedance spectroscopy results exhibit variations in the film resistance values at different potential along the polarization curve. Here, we would like to analyze the chemistry of the oxide film and the reason for the oxidation peaks observed in the polarization experiments. This can be done by carrying out depth proofing the initial oxide layer and the variations in the oxide film at the respective potentials would enable us to corroborate the electrochemical results.
Project Details
Project type
Exploratory Research
Start Date
2003-03-01
End Date
2005-03-03
Status
Closed
Released Data Link
Team
Principal Investigator