Determination of impedance parameters for mild steel/HCl interface using integration method

Abstract Impedance measurements for the interface between mild steel/hydrochloric acid as a function of cysteine (Cys) concentration were carried out for a wide enough frequency range. The validity of the impedance data was checked using the Kramers–Kronig (K–K) transforms. Despite the deviations at low frequencies for both transforms, imaginary-to-real and real-to-imaginary, a successful fit for the high frequencies was reached. The impedance parameters were determined from imaginary component of experimental impedance vs. log f diagrams using integration method and from complex plane plots fitting experimental results to an appropriate equivalent circuit. A compromise of parameters from two different plot methods was seen.