A comparison study on corrosion behavior of zinc phosphate and potassium zinc phosphate anticorrosive pigments

In this article, the effect of potassium on structure and anticorrosion properties of zinc phosphate pigments has been investigated. The co-precipitation method was selected as synthesis method of potassium zinc phosphate pigment. Then the synthesized pigment was characterized by x-ray diffraction XRD, Fourier transform infrared FTIR and Raman spectroscopy. Morphology of the powders was investigated with scanning electron microscope SEM. The inhibition efficiency of this pigment was compared to the commercial zinc phosphate pigment in a 3.5 NaCl solution by means of electrochemical impedance spectroscopy EIS on mild steel specimens. The surface composition of mild steel specimens after exposure to the test solutions was examined by energy dispersive X-ray spectroscopy EDS. The results indicate the better corrosion inhibitive performance of potassium zinc phosphate in comparison with the commercial zinc phosphate.