Corrosion inhibition of carbon steel by sodium metavanadate

The inhibition efficiency of sodium metavanadate (SMV)-adipic acid (AA) system in controlling corrosion of carbon steel in an aqueous solution containing 60 ppm of Cl- has been evaluated by weight-loss method; 250 ppm of SMV exhibits inhibition efficiency of 56 %. Addition of adipic acid to SMV improves the inhibition efficiency of the system. The formulation consisting of 250 ppm of SMV and 250 ppm of adipic acid has inhibition efficiency of 98 %. A synergistic effect exists between SMV and adipic acid with the synergism parameters greater than 1. Mecha¬nistic aspects of corrosion inhibition have been studied by electrochemical methods like potentiodynamic polarization and electrochemical impedance spectroscopy. FTIR spectra reveal that the protective film consists of Fe2+-SMV complex and Fe2+-adipic acid complex. The protective film has been analyzed by fluorescence spectra, SEM and EDAX

PORTUGALIAE ELECTROCHIMICA ACTA Inhibition of Corrosion of Carbon Steel in Sea Water by Sodium Gluconate -Zn 2+ System

Abstract The inhibition efficiency of sodium gluconate (SG)-Zn 2+ system in controlling corrosion of carbon steel in sea water has been evaluated by weight-loss method. The formulation consisting of 250 ppm of SG and 75 ppm of Zn 2+ has 98% IE. Influence of duration of immersion on the IE of SG-Zn 2+ has been evaluated. The mechanistic aspects of corrosion inhibition have been investigated by polarization study and AC impedance spectra. The protective film has been analysed by FTIR and luminescence spectra. The surface morphology and the roughness of the metal surface have been analysed by atomic force microscopy. The protective film consists of Fe 2+ -SG complex and Zn(OH) 2 . It is found to be UV -fluorescent