Some data on the dynamics of corrosion processes in water circulation cooling systems

Both origin and changes in phase composition of corrosion products deposite d 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. Th e predominant components of the corrosion products were initially found to be carbonates such as CaCO3 as well as hydroxycarbonates like Fe-2(OH)(2)CO 3; they were followed by the appearance of other products such as gamma -Fe OOH, Fe3O4, and alpha -FeOOH. The corresponding chemical reactions were fou nd to comply with first-order kinetics. The rate constants were calculated from changes in the relative intensities of the corresponding X-ray pattern s 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.