A study on Jordanian green natural agro-wastes as potential inhibitors of mild steel corrosion in HCl solution

Abstract

Mild steel is one of the most widely used materials in different engineering applications due to its mechanical properties, high availability and low cost. However, the exposure of the steel to acids such as hydrochloric acid (HCl) accelerates its corrosion rate. Green organic corrosion inhibitors are among the most effective materials for reducing the mild steel corrosion rate in an acidic medium. These inhibitors are environmentally accepted, easy to extract and non-toxic. This study investigated the feasibility of using different green Jordanian natural agro-wastes as green organic corrosion inhibitors and determined the efficiency of these inhibitors at different concentrations at room temperature. A potentiodynamic polarization test was performed in two sets of runs; the first set of runs was used to screen ten extracted green inhibitors and choose three based on their highest efficiency. In the second set of runs, the test was performed only on the highest-efficiency inhibitors selected from the first run. A weight loss test and Fourier transform infrared spectroscopy were also performed on the selected inhibitors. Based on the results of the tests, the green zucchini (Cucurbita pepo) leaf extract, oak (Quercus) leaf extract and okra (Abelmoschus esculentus) leaf extract were selected as inhibitors.