Aminopyrimidine derivatives as inhibitors for corrosion of 1018 carbon steel in nitric acid solution

The effect of some aminopyrimidine derivatives on the corrosion of 1018 carbon steel in 0.05 M HNO3 solution was studied using weight loss and polarization techniques. The percentage inhibition efficiency was found to increase with increasing concentration of inhibitor and with decreasing temperature. The addition of KI to aminopyrimidine derivatives enhanced the inhibition efficiency due to synergistic effect. The inhibitors are adsorbed on the steel surface according to Temkin isotherm. Some thermodynamic functions were computed and discussed. It was found that the aminopyrimidine derivatives provide a good protection to steel against pitting corrosion in chloride containing solutions.