Inhibition Efficiency of Goji Berry Extract Against the Corrosion of Carbon Steel SAE 1045

Corrosion degrades the surface of metals. Therefore, extracts of natural products are tested as possible corrosion inhibitors, in order to delay or inhibit such processes. These inhibitory substances can act via adsorption, forming a thin protective film that inhibits the anode and/or cathode processes on the surface. This study aimed to test the inhibitory efficiency of goji berry extract (GB) in the corrosion of SAE 1045 carbon steel. The extract was prepared by hydroethanolic extraction and was diluted with 0.5 mol L-1 NaCl electrolyte, for electrochemistry tests. The electrochemical impedance spectroscopy and anodic potentiodynamic polarization tests showed that the metal is more resistant to corrosion in the presence of the GB, because higher values of impedance and lower values of current density were obtained in the presence of the GB; the scanning electron microscopy data corroborated the electrochemical test results.