Inhibiting Action of Calcium Nitrite on Carbon Steel Rebars
Publication: Journal of Materials in Civil Engineering
Volume 13, Issue 1
Abstract
Corrosion rate studies were carried out on carbon steel rebar samples under different pH conditions and in the presence and absence of chloride ions in solution. A known amount of calcium nitrite was added as an inhibitor and the mechanism of inhibition was studied by tracking both the thermodynamic and kinetic properties of the system. The studies indicate that there is a competition between the corrosion and passivation reactions, and the resulting open-circuit potential depends on the relative strength of the corroding and passivating environments. The corrosion rate depends to a great extent on the pH of the solution. Nitrite ions act as anodic inhibitors by increasing the rate of formation of a barrier oxide film. The protective action of the nitrite ions seems to be more pronounced in highly corroding environment. This is due to the mechanism of inhibition, which uses the product of the unwanted corrosion reaction and converts it into a favorable passivating one. For a given amount of chloride, a minimum threshold concentration of nitrite is essential for protecting the steel.
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References
1.
Berke, N. S. ( 1989). “A review of corrosion inhibitors in concrete.” Mat. Perf., 28(10), 41–44.
2.
Berke, N. S., and Stark, P. ( 1985). “Calcium as an inhibitor: Evaluating and testing for corrosion resistance.” Concrete Int., 7(9), 42–47.
3.
Berke, N. S., Dallaire, M. P., Hicks, M. C., and Hoopes, R. J. ( 1993). “Corrosion of steel in cracked concrete.” Corrosion, 49(11), 934–943.
4.
Bockris, J. O., and Yang, B. ( 1991). “The mechanism of corrosion inhibition of iron in acid-solution by acetylenic alcohols.” J. Electrochem. Soc., 138(8), 2237–2252.
5.
Collins, W. D., Weyers, R. E., and Al-Qadi, I. L. ( 1993). “Chemical treatment of corroding steel reinforcement after removal of chloride-contaminated concrete.” Corrosion, 49(1), 74–88.
6.
Foley, R. T. ( 1975). “Complex ions and corrosion.” J. Electrochem. Soc., 11(22), 1493–1494.
7.
Fontana, M. G. ( 1986). Corrosion engineering, McGraw-Hill, New York, 445–473.
8.
Hope, B. B., and Ip, A. K. C. ( 1989). “Corrosion-inhibitors for use in concrete.” ACI Mat. J., 86(6), 602–608.
9.
Leek, D. S. ( 1991). “The passivity of steel in concrete.” Quarterly J. of Engrg. Geology, 24(1), 55–66.
10.
Page, C. L., Treadaway, K. W. J., and Bamforth, P. B., eds. ( 1990). Corrosion of reinforcement in concrete, Elsevier Science, New York.
11.
Rosenberg, A. H., and Gaidis, J. M. ( 1979). Mat. Perf., 18(11), 45–48.
12.
Stratmann, M., Furbeth, W., Grundmeier, G., Losch, R., and Reinartz, C. R. ( 1995). “Corrosion inhibition by adsorbed organic monolayers.” Corrosion mechanisms in theory and practice, J. Marcus and J. Oudar, eds., Marcel Dekker, Inc., New York, 373–420.
13.
Tonini, E. E., and Gaidis, J. M., eds. ( 1980). “Corrosion of reinforcing steel in concrete.” ASTM STP 713, ASTM, Philadelphia.
14.
Wagman, D. D., et al. ( 1981). “Selected values of chemical thermodynamic properties.” National Bureau of Standards Technical Notes 270-3 through 270-8, U.S. Government Printing Office, Washington, D.C.
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Received: Apr 23, 1998
Published online: Feb 1, 2001
Published in print: Feb 2001
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