Corrosion Inhibition of a Carbon Steel in 3% NaCl Solutions by Aliphatic Amino-Alcohol and Diamine Type Compounds

Abstract

Abstract Following the results previously obtained on the inhibiting effect of 2-ethylamino-ethanol, electrochemical corrosion rate measurement techniques (plotting of steady state polarization curves and polarization resistance measurements) were carried out in aerated and stirred 3% NaCl solutions containing various similar organic molecules (amino-alcohols and diamines). A comparative study of their efficiency was undertaken. Because most of these coumpounds exert a strong alkalizing effect on the saline solutions, they are characterized by means of the differential inhibitive efficiency concept which gives an account of the intrinsic inhibiting action of the compound and from which the influence of the pH rising is eliminated. The results of this comparative study corroborate the surface chelate formation as previously assumed to account for the intrinsic inhibiting action of 2-ethylamino-ethanol.