Stochastic processes of pit generation on zirconium with an anodic oxide film

The pit generation on zirconium with an anodic oxide film being formed in 1 N H2SO4 at different formation potentials and tested in 3.5% NaCl was analysed according to the stochastic theory. Pit generation on zirconium pretreated below 2V was found to agree with the parallel model of the birth stochastic process. For zirconium pretreated above 2 V the suitable model was found to be the birth and death stochastic model. The analysis suggested that the film formation potential, and consequently the film thickness as well as its properties, are important factors for controlling pitting corrosion of zirconium. (author)