Corrosion Inhibition of Carbon Steel in Hydrochloric Acid Solution using Non- Ionic Surfactants Derived from Phenol Compounds

摘要

Nonionic surfactants derived from phenol compounds inhibit the corrosion of carbon steel in 1.0 MHCl solution using galvanostatic polarization, electrochemical impedance spectroscopy, potentio- dynamic anodic polarization and weight loss techniques. The percentage inhibition efficiency of thesecompounds increases with increasing the concentration of inhibitors and number of ethylene oxideunits per molecule. Inhibition was explained on the basis of adsorption of these compounds on the steelsurface.The adsorption process obeys Langmuir isotherms. Polarization data suggested that the nonionic-surfactant molecules used as mixed type inhibitors. All impedance spectra tests exhibit onecapacitive loop indicating that the corrosion reaction is controlled by charge transfer process. Nonionicsurfactant compounds inhibit the pitting corrosion in chloride containing solutions by shifting thepitting potential into the noble direction.