Evaluation of Corrosion Inhibition Performance of Synthesized Potassium Zinc Phosphate Pigments in two Different Conditions During Immersion Time

In this research, the effects of changing in synthesis conditions on corrosion inhibition properties of the potassium phosphate pigment were studied. Processing parameters, including calcinations time, quiescent time, mixing rate and KOH/ZnCl2 mole ratio are selected as the influential parameters. Potassium zinc phosphate (PZP) pigments were prepared via co-precipitation method and their corrosion inhibition performance in a 3.5% NaCl solution was investigated during immersion time (1, 4 and 24 h). The synthesized pigments were characterized by x-ray diffraction (XRD) and Raman spectroscopy. Different analytical techniques including electrochemical impedance spectroscopy (EIS), inductively coupled plasma (ICP), pH measurement and surface analysis tests were employed in order to evaluate the corrosion inhibition performance of synthesized pigments in comparison with conventional zinc phosphate. The results revealed that the corrosion inhibitive performance of the PZP pigments is higher than that of the commercial zinc phosphate pigment. The evaluation of inhibition behavior in test solutions showed that by increasing the immersion time from 1 to 24 h charge transfer resistance of synthesized pigments increases. Considerable improvement in corrosion inhibition performance was observed by increasing the mixing rate and reducing the KOH/ZnCl2 mole ratio.