Electronic Thesis and Dissertation Repository

Degree

Doctor of Philosophy

Program

Chemistry

Supervisor

Dr. J.C. Wren

Abstract

This thesis presents work on the development of a mechanistic understanding of the effect of ionizing radiation on the aqueous corrosion kinetics of carbon steel. Exposed to ionizing radiation, water decomposes into a range of oxidizing (O2, •OH, HO2•, H2O2) to reducing (•eaq, •O2, •H) species. The production of the redox active species by radiolysis can have a significant effect on the corrosion behaviour of a metal. Of particular interest is the effect of radiolysis on corrosion when the solution environment, such as temperature, pH, and concentrations of chemical additives, changes over time. Since these solution parameters also affect the radiolysis behaviour, it was important to develop a clear understanding of separate effects of these parameters.

To achieve a better understanding, a number of electrochemical and surface analytical techniques were employed. The combination of electrochemical and surface analyses provided a picture of oxidation that largely resulted in the formation of a magnetite oxide layer, but the further oxidation, dissolution, and reactivity of the oxide was sensitive to all parameters studied. The production of water radiolysis products via gamma irradiation was seen to have a net oxidizing effect on the growing oxide film, increasing the oxide film resistance. At all temperatures studied, irradiation did not result in significant oxide structural changes or oxide film breakdown events.


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