Malvasylvestris Flower Extracts as Green Corrosion Inhibitor for Carbon Steel in HCl Solution

In this study, Malvasylvestris flower extract (MFE) was used as a corrosion inhibitor for carbon steel in 1 M HCl solution. Malvasylvestris extract was analyzed by gas chromatography coupled with a mass spectrometry detector (GC-MS). Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) studies revealed that the inhibition efficiency increases with increasing MFE concentration. Scanning electron microscopy (SEM) studies performed at various contact times of alloy with acid solution showed that the corrosion rate is reduced considerably in the presence of bioinhibitor. Corrosion studies at various temperatures (298 –338 K) showed that even at temperatures higher than 298 K the inhibition efficiency is good (>91%).Thermodynamic test results indicate that the MFE adsorption on the metal surface occurs by a chemisorption mechanism, and its adsorption isotherm is Langmuir.