Testing the protective ability of corrosion inhibitors in dilute chloride solutions

Abstract

After sterilization of meat cans in a factory of meat and meat products in Serbia, occurence of corrosion on the can lids was observed. Sterilization of cans is usually performed in the presence of corrosion inhibitors. The protective ability of commercial corrosion inhibitor P3 and corrosion inhibitor benzotriazole (BTA) in a solution of NaCl was examined in this work, using electrochemical impedance spectroscopy and recording the polarization curves. It is shown that in the presence of the above corrosion inhibitors, resistance of the electrolyte in the pores of an organic coating, which was applied to a can lid, increases several times, which indicates an improvement in barrier properties of the organic coating. In the presence of corrosion inhibitor P3, the corrosion rate of a metal in pores of the applied organic coating is about ten times lower, while in the presence of corrosion inhibitor BTA the corrosion rate is three to four times lower. Corrosion inhibitor P3 slows down anodic reaction in the corrosion process, more than cathodic reaction, unlike corrosion inhibitor BTA, which slows down cathodic reaction. Based on tests performed in this work, application of corrosion inhibitor P3 (in concentrations 0.6 to 1.0 g dm-3) is recommended during sterilization of meat cans in industry of meat and meat products.