PurposeThe purpose of this paper is to carry out laboratory studies of the inhibition effect of tyrosine (Tyr) on the corrosion of low chromium alloy steel (ASTM A213 grade T22) in 7 wt percent sulfamic acid solutions.Design/methodology/approachThe corrosion inhibitive effect of Tyr was investigated using electrochemical impedance spectroscopy (EIS) and the new technique electrochemical frequency modulation (EFM).FindingsIt was found that the inhibition efficiency increased with increasing inhibitor concentration, while a decrease was detected with the rise of temperature and stirring speed. The corrosion inhibition is due to physical adsorption of Tyr on the steel surface. Adsorption of the inhibitor molecule, onto the steel surface follows the Temkin's adsorption isotherm.Originality/valueThe obtained results from both methods (EIS and EFM) at different experimental conditions were in high agreement and almost similar. This is an indication that the EFM technique can be used efficiently for monitoring the corrosion inhibition under the studied conditions.