The Effect of Zn2+ Ions on the Corrosion Behavior of Tinplate Immersed in Food-Simulating Solutions

The influence of Zn2+ on the corrosion behavior of a commercial tinplate was studied in food-simulating solutions (0.1 M NaCl and 0.1 M citric acid/sodium citrate buffer solutions). The study was based on polarization and electrochemical impedance spectroscopy techniques. The corrosion inhibition afforded by Zn2+ was different depending on the nature of the electrolyte. The corrosion resistance of the tinplate samples immersed in NaCl solutions clearly improved with Zn2+ ion concentration, while no influence was observed for samples immersed in citric/citrate buffer solutions, regardless of the Zn2+ concentration. The surface morphology was characterized by scanning electron microscopy (SEM). The obtained SEM images corroborated the more severe attack suffered by samples immersed in citric/citrate solutions.