Dynamic impedance-based evaluation of inhibition efficiency using benzimidazole as a carbon steel corrosion inhibitor

The time-varying impact of benzimidazole (BI) on carbon steel corrosion in 1M HCl was investigated. Measurements were conducted under galvanostatic conditions using Dynamic Electrochemical Impedance Spectroscopy, with direct current set as zero providing free corrosion of metal. Also classical electrochemical methods were used. The manuscript demonstrates that inhibition efficiency significantly changes over time, from values over the 80% at the beginning to values even below the 40% for the lowest BI concentration at the end of experiment. The results show that the mechanism of corrosion prevention by the inhibitor is time-dependent. According to the data, the inhibition efficiency increases with increasing inhibitor concentration. The results enabled creation of a three-dimensional diagram used for prediction of inhibition efficiencies as a function of inhibitor concentration and time.