Abstract
The impedance characteristics of corroding iron was studied in acidic solutions with or without inhibitors, with special attention to the inductive impedance behaviour. The inductive behaviour, at low frequencies, was remarkable only in the sulphuric acid containing propargyl alcohol and it faded out with elapse of time. As expected from the theory of impedance, the corrosion reaction resistance Rcor, which is inversely proportional to the corrosion rate icor, was estimated from the impedances at high and low frequency. It was confirmed that the corrosion rates estimated from the impedance measurements and that of weight loss method were well consistent and the a-c corrosion monitor, devised by the authors recently, permitted to record the variation of corrosion rates even in the presence of inhibitors. The applicabilities of the a-c corrosion monitor were described.
