Corrosion Inhibition of Oxytetracycline for Cold Rolled Steel in HAc Solution in Presence of Cl^-

The corrosion inhibition of expired drugs oxytetracycline (OTC) for cold rolled steel (CRS) in 20% HAc solution in the presences of Cl- was investigated by mass loss, conductivity measurement and electrochemical methods. The results showed that OTC was a good inhibitor for cold rolled steel in 20% HAc solution in the presence of Cl-, and the inhibition efficiency increased with the increase of the inhibitor concentration, and the inhibition efficiency was up to 88.6% at the concentration of 7.0 g·L-1. It is a mixed-type inhibitor. The adsorption of inhibitors on the CRS surface is spontaneous physisorption and chemisorption, also obeys the Langmuir adsorption isotherm equation.