Corrosion Inhibition Effect of Carbon Steel in Sea Water by L-Arginine-Zn2+ System

The inhibition efficiency of L-Arginine-Zn2+ system in controlling corrosion of carbon steel in sea water has been evaluated by the weight-lossmethod. Theformulation consisting of 250 ppmof L-Arginine and 25 ppmof Zn2+ has 91% IE. A synergistic effect exists between L-Arginine and Zn 2+. Polarization study reveals that the L-Arginine-Zn2+ system functions as an anodic inhibitor and the formulation controls the anodic reaction predominantly. AC impedance spectra reveal that protective film is formed on the metal surface. Cyclic voltammetry study reveals that the protective film is more compact and stable even in a 3.5% NaCl environment. The nature of the protective film on a metal surface has been analyzed by FTIR, SEM, and AFM analysis.