Abstract

The use of coatings for metals protection against corrosion is an alternative to chromate treatment, restricted because of their high toxicity. Indeed, the chromate conversion processes show, the best results, however the use of Cr (VI) poses environmental problems.

Hexavalent chromium is toxic, carcinogenic and mobile in the environment. A green passivation treatment uses rare earth oxides, such as CeO2. At present, few studies have
focused on coatings on low carbon steel. The passivation treatment is carried out by cathodic
deposition from solutions of salts of cerium. Indeed, the formation of thin films is generally associated with the formation of cerium hydro-oxides on cathodic sites of the surface metal.

The electrochemical characterization of the coatings was evaluated in aggressive media as
NaCl 0.5 M and industrial water. For all samples, the characterization of the coatings is
monitored by measurement of the open circuit potential, polarization resistance as DC
measurement and by electrochemical impedance spectroscopy as AC measurement.

The electrochemical and analytical results have shown that the observed cracks of the coatings obtained on steel have implicated their good behavior against corrosion.

Keywords : thin films, rare earth, cathodic electrodeposition, Cerium oxide , Corrosion .

Information

Item Type:	Thesis
Divisions:
ePrint ID:	228
Date Deposited:	2014-12-17
Further Information:	Google Scholar
URI:	https://www.univ-soukahras.dz/en/publication/article/228

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