Enhancement of the corrosion resistance of zinc-aluminum-chromium coating with cerium nitrate

The present work aims at evaluating the effect of cerium nitrate on corrosion resistance of mild carbon steel coated by Dacromet in 3.5% NaCl solution. The scanning electron microscope (SEM) and energy dispersive X ray spectroscope (EDX) analysis were carried out to compare the surface structure and the composition of Dacromet coating and Dacromet+Re coating. The results of the electrochemical measurement showed that, compared with Dacromet coating, Dacromet+Re coating had a longer controlled sacrificial anodic protection function to steel substrate, a lower corrosion current density (icorr) and a higher corrosion potential (Ecorr). The modulus values of |Z| of Dacromet+Re coating is about 1 order of magnitude higher than that of Dacromet coating at low-frequency region.