Journal of Applied Electrochemistry, Vol.39, No.5, 569-576, 2009
Effect of sodium molybdate on the corrosion behavior of cold rolled steel in peracetic acid solution
The effect of sodium molybdate (Na2MoO4) on the corrosion of cold rolled steel (CRS) in peracetic acid (PAA) solution was investigated by gravimetric measurements, Tafel polarization curves, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). All the data indicate that Na2MoO4 acts as a very good inhibitor in PAA solution. The inhibition efficiency increases with increasing concentration of Na2MoO4 and immersion time. The inhibition efficiencies, calculated from gravimetric measurements, Tafel polarization curves and electrochemical impedance spectroscopy, are in reasonably good agreement and are very similar in the three cases. Furthermore, polarization data show that Na2MoO4 behaves as an anodic passive type inhibitor. Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM) were used to characterize the corrosion surface. A probable mechanism is presented to explain the experimental results.
Keywords:Sodium molybdate;Gravimetric measurements;Tafel polarization curve;Electrochemical impedance spectroscopy;Cold rolled steel;Peracetic acid