Inhibitive action of Cystine on the corrosion of low alloy steel ASTM A213 grade T22 in sulfamic acid solutions

The effect of Cystine on the corrosion behavior of low alloy steel ASTM A213 grade T22 in 0.5 M sulfamic acid solutions have been investigated by various electrochemical techniques. The study was performed using electrochemical impedance spectroscopy (EIS) and the recent technique electrochemical frequency modulation (EFM). The results of the investigation show that the inhibition efficiency increased with increasing inhibitor concentration, but decreased with increasing the solution temperature and stirring velocity. All the collected results from the two techniques are in good agreements, which confirm the ability of EFM technique for monitoring the corrosion inhibition under the studied conditions.