The Development of Corrosion Inhibitor for Zinc in Simulated Acidic Marine Atmosphere

Objective To inhibit the corrosion of zinc in atmosphere environment by looking for corrosion inhibitor formulations. Methods The inhibition behaviors of sodium polyphosphate and its mixtures with vanillin, potassium iodide and thiourea individually on zinc corrosion in simulated acidic marine atmosphere were investigated by means of static weight-loss test, polarization curve method and AC impedance spectroscopy. Results The result of static weight-loss test indicated that sodium polyphosphate and its mixtures all protected zinc from corrosion in simulated acidic marine atmosphere. The best quality ratios of sodium polyphosphate with vanillin, potassium iodide and thiourea individually were 3∶1, 1∶2 and 1∶4. Moreover, according to the result of the electrochemical test, it was found that sodium polyphosphate and its mixtures were mixed-type inhibitors and inhibited both of the cathodic reaction and the anode reaction. Sodium polyphosphate and its mixtures were able to form a layer of protective film on the surface of zinc, so as to inhibit the corrosion of zinc. Conclusion The corrosion inhibitor formulations can inhibit atmospheric corrosion of zinc effectively.