Silicone resin to improve corrosion resistance of Zn and ZnFe coated steel

dc.creatorSouza, M.E.P.
dc.creatorAriza, E.
dc.creatorBallester, M.
dc.creatorYoshida, I.V.P.
dc.creatorRocha, L.A.
dc.creatorFreire, C.M.A.
dc.date2006-01-01
dc.date2014-07-18T19:56:31Z
dc.date2015-11-26T13:21:35Z
dc.date2014-07-18T19:56:31Z
dc.date2015-11-26T13:21:35Z
dc.date.accessioned2018-03-28T21:05:06Z
dc.date.available2018-03-28T21:05:06Z
dc.identifierMatéria (Rio de Janeiro). Rede Latino-Americana de Materiais, v. 11, n. 1, p. 16-23, 2006.
dc.identifier1517-7076
dc.identifierS1517-70762006000100004
dc.identifier10.1590/S1517-70762006000100004
dc.identifierhttp://dx.doi.org/10.1590/S1517-70762006000100004
dc.identifierhttp://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-70762006000100004
dc.identifierhttp://www.repositorio.unicamp.br/jspui/handle/REPOSIP/38516
dc.identifierhttp://repositorio.unicamp.br/jspui/handle/REPOSIP/38516
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/1239978
dc.descriptionChromatation pre-treatments have been widely used to improve galvanized steel corrosion resistance. However, due to the high toxicity of chromate ions, chromatation pre-treatments tend to be banned and, in last years, alternative coating systems are under investigation. Recently, polysiloxanes have been developed for application as coatings. Among them, and due to their specific properties, such as hardness, chemical resistance and hydrophobicity, silicone resins may be considered as promising substitutes for chromatation pre-treatments. In this work silicone films, obtained from the hydrolysis of a methoxy functional silicone reactive intermediate, were applied on galvanized steel and on steel electroplated with a ZnFe alloy. Electrochemical techniques were used to characterize the degradation behavior of the samples. These consisted on the monitoring of the open circuit potential (OCP), and on the potentiodynamic polarization of the samples, which was performed in a 3% NaCl aqueous solution. Additionally, electrochemical impedance spectroscopy (EIS) was used as a complementary technique for the evaluation of the corrosion mechanisms of the coating system. SEM and EDS were employed to inspect the surface of the samples before and after the electrochemical tests. EIS data was fitted to an equivalent circuit from which the electrochemical parameters were obtained. Results show the protective character of the resin films, when compared with uncovered specimens. The capacitance of the films increased with the immersion time, in accordance to the behavior expected for an organic film. The overall performance of the coating systems appears to be highly dependent on the type of metallic coating applied to the steel. During the first three days of immersion the coatings applied upon galvanized steel showed larger |Z| values when compared with those applied to the electroplated steel, indicating a superior corrosion resistance of the former. However, after that time, an abrupt drop of |Z| is observed in the film applied on galvanized steel. In comparison, the coating system involving ZnFe alloy evidences a better stability throughout the immersion time.
dc.description16
dc.description23
dc.descriptionConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
dc.descriptionCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
dc.languageen
dc.publisherRede Latino-Americana de Materiais
dc.relationMatéria (Rio de Janeiro)
dc.rightsaberto
dc.sourceSciELO
dc.subjectSilicone Resin
dc.subjectZinc Alloy Coatings
dc.subjectElectrochemical Behaviour
dc.titleSilicone resin to improve corrosion resistance of Zn and ZnFe coated steel
dc.typeArtículos de revistas


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