Pre-Treatment of Niobium Phosphate for Protection against Carbon Steel Corrosion

This work proposes the development of a niobium phosphate coating (PNb) to replace the zinc phosphating, which is very aggressive to the environment and human health. The metallic material utilized was carbon steel (SAE 1010), which was coated with sunbathing - gel containing phosphate and niobium. A traditional zinc phosphate coating was used for comparison of results. The samples were characterized by scanning electron microscopy (SEM), dispersive energy spectroscopy (DES), open circuit potential, electrochemical impedance spectroscopy and anodic polarization. The results demonstrated that the samples coated with niobium phosphate have more surface nobility and greater corrosion resistance.