Abstract

In order to limit the degradation of steels in service, surface treatments are applied. The
combination of different layers to protect materials against corrosion in a sustainable manner. Based compounds of hexavalent chromium have always been the most used in the aerospace industry because they are simple to implement and are recognized as the most effective inhibitors of steel corrosion.

Recent European directives state that the use of compounds containing hexavalent chromium must be reduced or eliminated in the very near future, as they have been recognized carcinogenic to humans and toxic to the environment. Many studies have been made in recent years, but today, most alternatives do not pose the same level of performance as methods based on hexavalent chromium. An alternative treatments passivation uses rare earth oxides, in particular the Ce use the latter as an inhibitor to replace hexavalent chromium is characterized by forming thin layers is generally associated with the formation of oxides or hydroxides cerium cathodic sites of the metal surface.

The electrochemical characterization of the inhibition process was evaluated in harsh
environments such as 0.1 M NaCl, 0.1M Na2SO4 and industrial water. Thus, the corrosion
resistance obtained on steel A 366 was studied. For all samples, the duration of protection was assessed by measurement of Ecorr. In parallel, the efficacy is monitored by measuring the
polarization resistance, the corrosion current density of the lines extrapolated from Tafel
electrochemical impedance spectroscopy. In conclusion, the results of analytical and
electrochemical techniques have shown that cerium may very well and with similar efficacy
replaced hexavalent chromium.

Information

Item Type:	Thesis
Divisions:
ePrint ID:	287
Date Deposited:	2015-01-25
Further Information:	Google Scholar
URI:	https://www.univ-soukahras.dz/en/publication/article/287

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