The Influence of Cathodic Protection on Erosion-Corrosion of Metals and Model Alloys
Annual rept. 1 Dec 86-1 Dec 87
VIRGINIA UNIV CHARLOTTESVILLE DEPT OF CHEMICAL ENGINEERING
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The object of this program is to develop a fundamental understanding of the influence of applied potential on mechanisms for erosion-corrosion as applied to copper and copper-based alloys. This work is intended to allow application of laboratory experiments to predict the onset of erosion-corrosion failure under field conditions and to guide development of workable strategies for prevention of erosion-corrosion. In the first year of the program, an electrochemical cell incorporating a scanning ellipsometer was designed and built. The cell uses a submerged electrolyte jet impinging on an electrode. The laser spot is around 25 X 70 micrometers and the position of the electrode-jet assembly relative to the laser spot can be controlled by stepping motor stages without altering the hydrodynamic environment. This system will be used to map local film thickness under well controlled fluid flow exhibiting high shear rates. The radial position at which the film thickness decreases can be related to a critical value for hydrodynamic shear required to remove the film, and the use of a well-characterized flow geometry allows separation of erosion-corrosion effects from corrosion enhancement associated with mass transfer. Experiments using this system will begin in the second year of the program.
- Inorganic Chemistry
- Properties of Metals and Alloys