In this study, cerium-based conversion coating was deposited on steel X52 by dip immersion method. Cerium oxide/hydroxide is an environmentally friendly conversion coating. The effects of immersion times and immersion temperatures on corrosion properties of cerium conversion coating on steel X52 were studied. Its corrosion resistance in 3.5 wt.% NaCl solution was investigated by means of electrochemical impedance spectroscopy, potentiodynamic polarization, and surface techniques. The coated samples showed a significant decrease in corrosion rate and corrosion current decreased with increasing immersion time up to 60 s. In addition, electrochemical impedance data showed that in the presence of cerium oxide conversion coatings, the charge transfer resistance of aluminum increased. The experimental results indicated that the corrosion resistance decreased with increasing the operating temperature. Surface morphology and its chemical composition were analyzed by means of scanning electron microscopy and energy dispersive spectroscopy.
Keywords:
Steel X52; Cerium oxide coatings; Impedance; SEM
