Protective properties of the chromium–titanium carbonitride composite coatings

The corrosion behavior of chromium and chromium–titanium carbonitride (TiCN) composite coatings in acidic sulfate solution was studied by the potentiostatic polarization and impedance spectroscopy methods. The data obtained were compared with the results of corrosion tests in the corrosion chamber of salt spray. Corrosion behavior of coatings was studied in relation to their microstructure and composition. The results obtained have shown that the incorporation of high-dispersed TiCN particles into Cr coating led to an increase in their corrosion resistance. Analysis of electrochemical impedance spectroscopy data obtained for different immersion times suggest that the enhanced corrosion resistance of Cr–TiCN coating may be attributed to microstructural features of this coating, containing smaller pores than Cr coating.