Morphology and Corrosion Resistance of Cr(III)-based conversion treatments for electrogalvanized steel

The effectiveness of Cr(VI)-based passivation treatments is well accepted but there are many problems with regard to their environmental suitability. Because these compounds are carcinogenic and toxic, eco-friendly systems capable of replacing them are being evaluated. In this work, the corrosion be...

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Detalles Bibliográficos
Autores: Tomachuk, C. R., Elsner, Cecilia Inés, Di Sarli, Alejandro Ramón, Ferraz, O. B.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2010
País:Argentina
Institución:Universidad Nacional de La Plata
Repositorio:SEDICI (UNLP)
Idioma:inglés
OAI Identifier:oai:sedici.unlp.edu.ar:10915/81952
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/81952
Access Level:acceso abierto
Palabra clave:Química
Conversion treatment
Corrosion
Green technologies
Impedance spectroscopy
Salt spray
Zinc
Descripción
Sumario:The effectiveness of Cr(VI)-based passivation treatments is well accepted but there are many problems with regard to their environmental suitability. Because these compounds are carcinogenic and toxic, eco-friendly systems capable of replacing them are being evaluated. In this work, the corrosion behavior in 0.5 M NaCl solution of zinc coatings deposited from a free-cyanide alkaline bath and treated with Cr3+ based passivation coatings were characterized through DC and EIS techniques. The salt spray test as well as studies of the surface structure and chemical composition were also performed. From these analyses it was inferred that (1) the greencolored Cr3+ passivated coatings provide better corrosion resistance than the yellow- and blue-colored coatings, and (2) together with an adequate painting system, they could be a less polluting and less toxic alternative to traditional chromate coatings.