ABSTRACT
In this article, the corrosion inhibition of steel DIN 2391 St 37-4 in acidic medium 5% H2SO4 with and without the presence of eco inhibitors of leaf (Petroselinum Sativum) was examined. Inhibitory properties of parsley leaves (Petroselinum Sativum) on steel DIN 2391 St 37-4 were examined by potentiodynamic polarization - Tafel extrapolation, and FTIR method in order to categorize the oxide layer. The test was performed in static medium and with stirring at 600 rpm. By Tafel extrapolation based on changes in corrosion potential, the inhibitor behaves as mixed. Increasing the concentration of inhibitors increases the efficiency of inhibition. Corrosion processes are inhibited by adsorption of organic matter on the surface of steel DIN 2391 St 37-4, forming a film. The obtained results indicate that parsley leaf (Petroselinum Sativum) is an effective eco inhibitor for the tested steel in 5% sulfuric acid.