Mild steel corrosion inhibition by some heteroatom organic compounds in acetic acid medium

Four heteroatom organic compounds (HAC) such as L-methionine (Meth), L-Cysteine (Syst), Phenyl MercaptoTetrazol (PMT) and Glutamic acid (GA) were evaluated as corrosion inhibitors for mild steel in 1M acetic acid (AcA) solution. The technique used are potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), UV-Vis spectroscopy analysisand scanning electron microscopy (SEM). As a comparative study results, the corrosion inhibitor rankings were: Meth ˂ Cyst ˂ PMT ˂ GA. Furthermore, the GA was the best inhibitors against mild steel corrosion and provided an inhibition efficiency of 74% at 10 -4 M. For this reason, we have besides studied the GA concentration and immersion time on the performance delivered by GA. In this way, it is affirmed that the inhibition efficiency was well improved with the GA concentration increasing. In addition, the GA is a good corrosion inhibitor even with long durations.