## Abstract Potentiodynamic anodic polarization curves have been traced for an electrode of the steel Deltaβ52 (0.40, 0.78Mn, 0.045 S, 0.06P, 0.23 Si): the aggresive media used were potassium hydroxide without and with additions of potassium chloride, bromide and iodide. The oxide film present on t
A Contribution to the Study of the Critical Pitting Potential of Oxide Covered Aluminum in aqueous chloride solutions
β Scribed by Z. A. Foroulis; M. J. Thubrikar
- Publisher
- John Wiley and Sons
- Year
- 1975
- Tongue
- German
- Weight
- 762 KB
- Volume
- 26
- Category
- Article
- ISSN
- 0947-5117
No coin nor oath required. For personal study only.
β¦ Synopsis
Abstract
The critical pitting potential of oxide covered aluminum electrodes in aqueous chloride solutions has been investigated as a function of chloride ion concentration, temperature, solution pH and oxide film thickness. The steady state critical pitting potential decreases with chloride ion concentration and increasing solution temperature. Solution pH in the range 5 to 9 has no effect on the breakdown potential. The role of the oxide film thickness is to slightly increase the critical potential for passivity breakdown and intiation of pitting. It is postulated that at the critical pitting potential, passivity breakdown occurs by a process of field assisted Cl adsorption on the hydrated oxide surface and formation of a soluble basic chloride salt with a lattice cation which readily goes in solution. This process of localized dissolution of the hydrated oxide film via formation of a soluble basic aluminum chloride salt, once initiated, is likely to continue in an βautocatalyticβ fashion until the oxide is locally βpenetratedβ and dissolution of the substrate metal begins.
π SIMILAR VOLUMES
## Abstract The way in which the stationary potential of a zinc electrode previously treated with various passivating and inhibiting solutions changes in the present of the chloride, bromide and iodide ions is studied in solutions of potassium chromate, disodium hydrogen phosphate and sodium tungst
The distribution method was modified in several directions: petroleum ether was used as extracting solvent; the ratio of the volumes of the organic and aqueous phases was varied so as to keep the weight of the amine in the aqueous phase approximately equal to that in the organic phase; and the amine
The potential of Γy ash procured form coal-Γred thermal power plants was studied as a heterogeneous catalyst in the oxidation of aqueous sodium sulΓde solutions with hydrogen peroxide in the temperature range of 303Γ323 K. The e β ects of various parameters (source of Γy ash, Γy ash loading, initial
Light scattering measurements have been performed on aqueous solutions of undecylammonium chloride in the presence of 0 to 0.2 mol dm(-3) NaCl and 0 to 0.5 mol dm(-3) n-butanol at 25 degrees C. The critical micelle concentration (CMC), aggregation number, and degree of dissociation of the micelles h