Effect of Immersion Time on the Corrosion Behavior of Mild Steel in Sulfuric Acid with Salvia officinalis Inhibitor

This study investigates the impact of immersion time on the corrosion inhibition efficiency of Salvia officinalis (sage) essential oil extract for mild steel in 1 M H₂SO₄ by using the gravimetric (weight loss) method. Experiments were performed under constant conditions of inhibitor concentration, temperature, and acid concentration, with different exposure periods ranging from 12 to 72 hours. The results show that the inhibition efficiency of sage essential oil extract increases when immersion time is increased, reaching about 71% at 72 hours. The corrosion rate and weight loss of mild steel responded positively with the addition of inhibitor essential oil extract to 1.0 M H₂SO₄. A drop of almost 3 and 2.5 times less was achieved for corrosion rate and weight loss respectively. The results suggest that sage is a potent green inhibitor, and its performance improves over time due to a more favorable surface interaction, providing the ability to provide long-term protection for mild steel in acidic environments.