The objective of this project is the measurement of crevice corrosion damage functions that can be used either to develop models of waste package damage accumulation due to crevice corrosion or to validate alternative models for the same purpose. The key deliverables will be direct measurements of the time-dependence of the depth and distribution of corroded sites within a well-defined crevice area for corrosion resistant alloys exposed to aggressive conditions. Samples will be obtained from other workers within the Corrosion CoOp (Univ. of Western Ontario, AECL) that have been crevice corroded under controlled conditions for known periods of time. Confocal Laser Scanning Microscopy (CLSM) will be used to develop quantitative descriptions of the corrosion damage via imaging of the cavities created by the metal dissolution. The CLSM will allow quantitative, three-dimensional characterization of the corrosion attack. The damage will be characterized quantitatively by the total volume lost, the distribution of thickness loss, as well as the occurrence of any other forms of localized corrosion (e.g., pitting, intergranular corrosion). These data will be compared to the electrochemical and surface analytical data collected by the creators of the crevice samples. In this way, the effect of alloy composition, solution composition, temperature, cathode-to-anode area ratio, and time can be determined.
|Confocal Microscope image of crevice corrosion attack of Type 316L SS
(by A. Hodges)