Green inhibitor for corrosion protection of ASTM A1011 steel in saline medium using a dynamic system

Currently, inhibitors represent an economical option for protecting metals against corrosion. However, most inhibitors are synthetic and harmful to the environment. The present study focuses on estimating the anticorrosive effect of Oreocallis grandiflora extract (OGE) on ASTM A1011 steel immersed in a 3.5 wt.% NaCl solution. The investigation was carried out using open circuit potential (OCP) and potentiodynamic polarization curves to different concentrations of OGE in saline solution using a dynamic system. The results of potentiodynamic polarization curves indicated that the corrosion rate of ASTM A1011 steel decreased as the OGE concentration was increased. This inhibitor demonstrated an efficiency of 64 to 88 % in enhancing the corrosion resistance of the steel substrates. The value of the free energy of adsorption was -23.59 kJ mol-1, indicating that the OGE molecules are spontaneously adsorbed onto the surface of the substrate. The results of this study showed that Oreocallis grandiflora extract has high potential as a green corrosion inhibitor, as it forms a barrier between the substrate and the corrosive solution.