CIDEPINT   05376
CENTRO DE INVESTIGACIONES EN TECNOLOGIA DE PINTURAS
Unidad Ejecutora - UE
artículos
Título:
Tratamientos de Conversión Atóxicos y Eco-Compatibles para la Protección de Acero Electrocincado.
Autor/es:
A. R. DI SARLI; C.R. TOMACHUK; C. I. ELSNER
Revista:
INGENERARE
Editorial:
Facultad de Ingeniería de la Pontificia Universidad Católica de Chile,
Referencias:
Lugar: Valparaiso; Año: 2012 vol. 26 p. 21 - 28
ISSN:
0718-1442
Resumen:
The corrosion resistance of pure zinc coatings can beimproved through the application of suitable chemical passivationtreatments. Hexavalent chromium compounds have widely been usedto formulate conversion layers providing better anticorrosive protectionas well as anchorage properties to painting systems. However, takinginto account that they are produced using hazardous chemical ingredients,the development of alternative and “green” technologies withequivalent protective performance is a paramount purpose of manyR&D laboratories working around the world. In the present paper, thecorrosion behavior of zinc coatings obtained from free-cyanide alkalinebaths and latterly subjected to a Cr3+ based passivation treatment, with and without a sealing treatment, was studied. The experimental work involved electrochemical impedance spectroscopy measurements in 0.5 M Na2SO4 solution, surface microstructural and morphological characterization by electronic microscopy as well as chemical analysis by EDXS. The analysis and interpretation of all the data coming from these battery of tests allowed inferring that both the Cr3+ based conversion treatment + adequate sealer presented a good corrosion resistance and, therefore, they could be used as a none polluting nor toxic alternative to the traditional chromate coatings.