The Inhibition Effect of Some Organic Compounds on Corrosion of Brass and Carbon Steel in Aggressive Medium

摘要

The surfactants Triton X100 and Triton A20 were studied as corrosion inhibitors for brass and carbonsteel type OL37 in sulfuric acid medium using potentiodynamic polarization measurements,electrochemical impedance spectroscopy (EIS), FT-IR spectroscopy and metallurgical microscopymethods. We suppose that, these surfactants inhibit corrosion of metal electrodes by a protectivemechanism can be owed to either the adsorption of inhibitor molecules forming a protective film orobtaining a insoluble compound and repairing the porous oxide layers. Experimental data showed thatthese surfactants achieved a significant inhibiting effect on brass and carbon steel corrosion and actthat a mixed inhibitor. The adsorption of the non-ionic surfactants on the electrodes surface obeys tothe Langmuir isotherm model. The temperature influence on the corrosion behaviour of the metalelectrode in 0.5M H2SO4 with and without the inhibitor at 100 ppm and 800ppm was analyzed in thetemperature domain from 293 to 313 K. The negative value of thermodynamic parameter like Gibbsfree energy of adsorption shows the spontaneity of adsorption process. The experimental resultsindicate that these inhibitors established its corrosion protection ability. The best effectiveness isachieved at the inhibitor concentration of 100ppm for the system Triton X100/OL 37 and 800ppm forTriton A20/brass.