A Correlated Potentiostatic Microscopic Study of Iron Passivation in Sulfuric Acid

Autor:	H. B. Kirkpatrick, A. Pigeaud
Rok vydání:	1969
Předmět:	Materials science Passivation General Chemical Engineering Inorganic chemistry Oxide Sulfuric acid General Chemistry Electrolyte Polarizer Reflectivity Half-cell law.invention chemistry.chemical_compound chemistry Colloidal particle law General Materials Science
Zdroj:	CORROSION. 25:209-214
ISSN:	1938-159X 0010-9312
DOI:	10.5006/0010-9312-25.5.209
Popis:	Microscopic observations of surface and liquid phase processes are correlated with changes in the electrical output of an iron half cell undergoing cyclic activation and passivation in 1N sulfuric acid. When observed with crossed polarizers, no optical changes are seen during the activation step, but during the current decay associated with the onset of passivation, a roughly circular zone of greatly increased reflectance is seen to grow from the circumference of the specimen towards its center. The light emanating from this zone appears to be completely depolarized, and by ultra-microscopy, it is seen to contain colloidal particles. It is also seen that while the electrical and optical characteristics of the surface during the activation step are insensitive to flow conditions in the electrolyte adjacent to the surface, those during the passivation stage are very sensitive. It is suggested that prior to the establishment of a coherent passive oxide film on the iron surface, there is a precursory...
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::1a9c73050e520ce2d8d66b09689bf789 https://doi.org/10.5006/0010-9312-25.5.209 Zobrazit plný text záznamu