Laboratory assessment of inhibition efficiency and mechanism of inhibitor blend (P22SU) on mild steel corrosion in high chloride containing water

Abstract

The corrosion inhibition process of phosphonic-acid based inhibitor blends (Corin P22SU), on mild steel corrosion in simulated cooling water (SCW) containing chloride ion has been investigated using electrochemical methods (impedance spectroscopy (EIS), open circuit potential (OCP) and visual characterization). The synergistic effect on the inhibition efficiency of the commercially produced (Corin P22SU) inhibitor with different concentrations of nitrite was examined. Inhibition activity increases with the increase of Corin P22SU concentration. The experimental parameters were concentration of the inhibitor, and soaking time. P22SU inhibits mild steel corrosion in near neutral and alkaline (pH ≥ 6) SCW. Inhibitive action was increased with the increase of soaking time up to six hours and afterwards. Based on the experimental results, mechanisms of action of Corin P22SU on mild steel corrosion inhibition in SCW have been proposed.