Experimental Analysis of Gmelina Leave Inhibitor on the Corrosion Rate of Mild Steel in HCl Solutions

Corrosion of mild steel in acidic environments poses significant challenges in various industries, leading to material failure and economic losses. This research therefore investigates the potential of Gmelina leaf extract as a sustainable and eco-friendly corrosion inhibitor for mild steel in hydrochloric acid (HCl) solutions. The aim of this research is to assess the inhibitor's effectiveness in reducing the corrosion rate of mild steel at different HCl concentrations. Results showed that without the inhibitor, the corrosion rate increased with HCl concentration, ranging from 0.754 mm/yr at 0.47 mol/dm³ to 4.667 mm/yr at 2.39 mol/dm³. However, in the presence of the Gmelina leaf inhibitor, the corrosion rate was significantly reduced, with values ranging from 0.090 mm/yr at 0.47 mol/dm³ to 0.918 mm/yr at 2.39 mol/dm³, achieving inhibition efficiencies between 80% and 88%. This research provides new insights into the high effectiveness of Gmelina leaf extract in forming a protective barrier on the steel surface, reducing corrosion even in highly acidic environments. The study highlights this leaf extract as a green, cost-effective alternative to synthetic inhibitors, with wide applications in industries requiring corrosion protection in harsh acidic conditions. Keywords: Corrosion, Mild Steel, Gmelinas, Hydrochloric Acid.