Mass transfer influence on the corrosion inhibition of N80 steel in 1 M H₂SO₄ by green corrosion inhibitor using MATLAB

The corrosion process of steel alloys in acidic environments is typically considered to be governed by charge transfer (activation) control. Nonetheless, in aerated solutions, mass transfer can affect the electrochemical measurements. This study examines the corrosion inhibition of N80 steel in 1 M sulfuric acid using okra leaf extract (OLE), utilizing electrochemical polarization techniques at various concentrations of the inhibitor and different temperatures. The outcomes of electrochemical data of current densities and overpotentials were fitted to a high-order polynomial equation and the Maclaurin series formula. The coefficients of the high-order polynomial equation were evaluated using a non-linear regression method, which is in turn used in the Maclaurin series formula. A series of complex equations were derived, incorporating a factor (β) to account for the impact of mass transfer on the activation-controlled corrosion process. A complex equation set of β-models was processed using MATLAB computer programming. In addition, a β-model was correlated to a mass transfer correction factor (γ) and polarization resistance (R_p). β-values ranged from 0.005 to 0.916 (average 0.198), which indicates the presence of a mass transfer effect in addition to the activation effect (mixed control corrosion mechanism). Conversely, the polarization resistance (Rp) increased with higher inhibitor concentrations and decreased as the temperature rose.