THE INHIBITIVE EFFECT OF DIETHYLENE TRIAMINE PENTAMETHYLENE PHOSPHONIC ACID ON THE CORROSION OF CARBON STEEL IN SEAWATER

摘要

The inhibition of the corrosion of carbon steel in seawater by diethylene triamine pentamethylene phosphonic acid (DTPMP) and Ni 2+ has been investigated using weight loss and electrochemical measurements. The results show that 70% inhibition efficiency is achieved with binary system consisting of 250 ppm of DTPMP and 50 ppm of Ni 2+ .Polarization curves indicate that the system functioned as a cathodic inhibitor. AC impedance spectra reveal that a protective film is formed on the metal surface. The protective film has been analysed by FTIR spectra. The surface morphology and the roughness of the metal surface have been analysed by atomic force microscopy.