Some Data on the Dynamics of Corrosion Processes in Water Circulation Cooling Systems

Abstract

Both origin and changes in phase composition of corrosion products deposited on Standard Carbon Steel during 313 days of exposure were monitored by X-ray diffraction analysis. The corrosion was caused by water from industrial cooling systems in the presence as well as in the absence an inhibitor. The predominant components of the corrosion products were initially found to be carbonates such as CaCO3 as well as hydroxycarbonates like Fe2(OH)2CO3; they were followed by the appearance of other products such as γ-FeOOH, Fe3O4, and α-FeOOH. The corresponding chemical reactions were found to comply with first-order kinetics. The rate constants were calculated from changes in the relative intensities of the corresponding X-ray patterns of Standard Carbon Steel samples. In absence of the inhibitor the rate of the corrosion processes were found to be 2.3 to 3 times higher than in its presence.