Corrosion inhibition performance of Cephradine for Q235 steel in acetic acid solutions containing chloride ions

The corrosion inhibition performance of expired Cephradine for Q235 steel in 20% acetic acid solution containing 600 mg L-1 chloride ion has been studied by Tafel polarization curve and electrochemical impedance spectroscopy (EIS). The results show that Cephradine is a good mixed-type inhibitor mainly controlled by cathode, and its adsorption on the Q235 steel surface is in accordance with Langmuir monolayer adsorption. The variation of corrosion inhibition rate with Cephradine concentration, immersion time, and solution temperature was studied. The optimal corrosion inhibition concentration of Cephradine is 1.5 x 10(-2) mol L-1 at 298 K for 2h, and the inhibition rate reached 86.70%. The inhibition rate reached 96.23% in optimal concentration at 328K for 2h and 96.83% in optimal concentration, 298K for 32h. The scanning electron microscope (SEM), Adsorption model and Electrical conductivity (EC) effectively verified the results.