Corrosion Resistance and Morphological Behaviour of Vanadium Based Conversion Coating on Carbon Steel Surface

The influence of vanadium based conversion coating (VCC) on the corrosion resistance and morphology of carbon steel substrate was evaluated by linear polarization resistance (LPR), open circuit potential (OCP) and optical microscopy (OM) techniques. The conversion coating parameters such as bath pH, vanadium ion concentration (C) and substrate immersion time (t) are optimized in VCC bath containing aqueous vanadium pentoxide solution. The LPR results demonstrated that the highest polarization resistance (Rp) of coatings can be obtained when the samples are immersed in the conversion bath containing V2O5 with concentration of 0.05 gr/lit for 60 seconds at pH=3. The optical micrographs revealed surface roughness increment of carbon steel as a result of ununiform VCC formation on the surface.

کلیدواژه ها:

Vanadium conversion coating ، LPR ، Optical Microscopy ، Carbon Steel ، Corrosion