242INHIBITION OF CORROSION OF CARBON STEEL IN SEAWATER BY 2-CARBOXYETHYL PHOSPHONIC ACID AND NI2+ SYSTEMThe inhibition of the corrosion of carbon steel in seawater by 2-carboxyethyl phosphonic acid (2-CEPA) and Ni2+ has been investigated using weight loss and electrochemical measurements. The results show that 73% inhibition efficiency is achieved with binary system consisting of 250 ppm of 2-CEPA and 50 ppm of Ni2+. Polarization study reveals that 2- CEPA – Ni2+ formulation functions as a cathodic inhibitor, which controls the cathodic reaction predominantly and to some extent controls the anodic reaction. AC impedance spectra reveal that a protective film is formed on the metal surface. Surface evaluation techniques like FTIR and SEM were used to determine the nature of the protective film formed on the metal surface.sennikavi@yahoo.co.inReview562015Corrosion Inhibition,Synergistic Effect,Electrochemical Techniques,FTIR,SEMK. Kavipriya,J. Sathiyabama,S. RajendranDepartment of Chemistry, PSNA College of Engineering and Technology, Dindigul, Tamilnadu, India 624 622,Corrosion Research Centre, PG and Research Department of Chemistry, GTN Arts College, Dindigul, Tamilnadu, India 624 005,RVS School of Engineering and Technology, Dindigul, Tamilnadu, India 624 005