The Inhibitory Action of Aniba Canelilla (H. B. K.) Mez. Extracts on the Corrosion of Carbon Steel in Hydrochloric Acid Medium

The use of eco-friendly corrosion inhibitors in metallurgical processing has increased interest due to the reduced environmental impact. Hence, the inhibitory effect of Aniba canelilla (Lauraceae) extract was studied in the corrosion of carbon steel in 1.0 mol∙L-1 hydrochloric acid solution. This acid is used during the surface treatment of steel processing. The carbon steel protection was observed by varying the extract concentration from 50 to 300 mg∙L-1. Polarization curves revealed that this extract acted as an adsorption inhibitor decreasing both anodic and cathodic current densities. A relatively high inhibition corrosion efficiency, close to 97%, was obtained with plant stem extracts by gravimetric measurements. Weight loss measurements showed that the extract remains active for at least 72 hours at room temperature. The adsorption process of this extract is properly represented by the Langmuir isotherm. Atomic force microscopy shows that inhibited acid medium produces a smooth surface.