Corrosion Inhibition of Kudingcha Extract for N80 Steel

The corrosion inhibition of kudingcha (KDC) extract for N80 steel in solution with 3.5% (mass) NaCl and saturated CO₂ was investigated by Fourier transform infrared spectroscopy (FTIR), gas chromatography-mass spectrometry (GC-MS), electrochemical impedance spectroscopy (EIS), polarization curve and scanning electron microscopy (SEM). The results show that the KDC extract was a mixed-type inhibitor. The KDC inhibitor had a certain corrosion inhibition for N80 steel in solution with 3.5% NaCl and saturated CO₂. The inhibition efficiency increased with the concentration of inhibitor. When the volume fraction of the inhibitor was 4%, the inhibition efficiency reached 92.47% and 96.90% calculated according to polarization curve and electrochemical impedance spectroscopy, respectively.