Inhibitory action of aqueous garlic peel extract on the corrosion of carbon steel in HCl solution

The effect of aqueous garlic peel extract on the corrosion process of carbon steel in 1 mol L−1 HCl was examined. The inhibition efficiency of C-steel in 1 mol L−1 HCl increased as the extract concentration and temperature increased. The inhibitory property of the extract is discussed in terms of the mechanism by which its components adsorb onto the C-steel surface. This adsorption process obeyed a Langmuir adsorption isotherm. HS-SPME GC analysis of the garlic peel extract suggests that sulphur compounds may play an important role in the inhibition process.

► Garlic peel extract can act as corrosion inhibitor for C-steel in acid solution.
► The extract acted as mixed-type inhibitor on the C-steel surface.
► The inhibition efficiency increased with the extract concentration and temperature.
► The Ea of C-steel dissolution decreased in the presence of the extract.
► The sulphur compounds may play an important role in the inhibition process.