In order to screen low-cost and environmentally friendly corrosion inhibitors in trichloroacetic acid (Cl3CCOOH) solution, the corrosion inhibition performance of anionic surfactant of sodium dodecyl sulfate (SDS) on cold rolled steel in trichloroacetic acid (Cl3CCOOH) solution was studied by weight loss and potentiodynamic polarization curves. The corrosive micro-topography and the change of hydrophilic/hydrophobic properties of steel surface were studied systematically by scanning electronic microscope (SEM), atomic force microscope (AFM) and contact angle instrument. Results showed that SDS could effectively retard the corrosion of cold rolled steel in 0.10 mol/L Cl3CCOOH solution, and the inhibition efficiency increased with the increase of SDS concentration. The maximum inhibition efficiency was up to 90.5% at 20 ℃ with just adding 50 mg/L SDS. Moreover, the adsorption of SDS on steel surface obeyed Temkin adsorption isotherm, and the standard adsorption Gibbs free energy was -27.3 kJ/mol. The presence of SDS shifted corrosion potential to negative position. The cathodic reactions were efficiently retarded, and yet there was no obvious inhibition effect on anodic reactions. In the presence of SDS, the result of SEM and AFM clearly showed the corrosive degree and surface roughness of steel in Cl3CCOOH solution significantly were reduced, and contact angel measurements indicated the hydrophobic angle increased.
