A Novel Mathematical Method for Equivalent Circuit Modeling Determination for Electrochemical Impedance Spectroscopy to Study Corrosion Behavior of Corrosion Resistant Steel

A novel mathematical method is presented to determine equivalent circuit modeling based on electrochemical impedance spectroscopy (EIS) dates, and to investigate the corrosion behavior of corrosion resistant steel for cargo oil tank (COT) in NaCl acid solution. First, the corrosion rate is calculated by weight loss method, it indicates superior corrosion resistance. Next, the transfer function of system is obtained by the electrochemical impedance spectroscopy (EIS) dates, and determines proper time constants for equivalent circuit to fit experimental results. Finally, the results of EIS are in agreement with accelerated corrosion measurements by the fitting errors and relating to known physical parameters, which indicate the novel mathematical method is very effective.