Effect of octadecylamine on the corrosion behavior of Type 316SS in acetate buffer

The inhibitory effect of octadecylamine (ODA) on the corrosion and passivity breakdown of Type 316SS in acetic acid solution was characterized using potentiodynamic polarization, cyclic voltammetry, and electrochemical impedance spectroscopy (EIS). The inhibition mechanism of ODA was defined by optimizing the Bi-layer Point Defect Model on the EIS data. The optimization results indicated that, as either the concentration of ODA or the immersion time increases, the inhibitor-modified outer layer resistance, the charge transfer resistance, and the Warburg coefficient for the transport of species through the porous outer layer of the passive film all increase, thereby accounting for the observed inhibition.