Electrochemical methods were used to evaluate sodium phosphate and sodium nitrite as inhibitors for the corrosion of steel in saturated calcium hydroxide solution containing chloride ions. The studies included immersion, potentiodynamic, potentiostatic, and galvanostatic tests. The results obtained from these methods were in good agreement. They show that sodium nitrite is an anodic inhibitor which is not effective if its concentration is lower than that of the chloride ions. Sodium phosphate acts as an anodic inhibitor if its concentration is higher than 0·6 times the chloride concentration. It is totally effective when its concentration equals the chloride concentration.
Get full access to this article
View all access options for this article.
References
1.
BerkeN. S.: in ‘Corrosion effect of stray currents and the techniques for evaluating corrosion of rebars in concrete’, STP906, 78–91; 1986, Philadelphia, ASTM.
2.
Jarrat-KnockD. G., BROMWICHA., and DRANSFIELDJ. M.: Proc. 4th Int. Symp. on ‘Corrosion of reinforcement in concrete construction’, 590–595; 1996, London, Society of Chemical Industry.
3.
MercerA. D., JENKINSI. R., and RHOADES-BROWNJ. E.: Br. Corros. J., 1968, 3, 136–144.
4.
DhouibiL., TRIKIE., and RAHARINAIVOA.: Proc. Conf. on ‘Understanding corrosion rates on steel in concrete’, July1997, Cambridge, MA, USA.
5.
AcostaC. A., SALVAREZZAR. C., VIDELAH. A., and ARVIAA. J.: Corros. Sci., 1985, 25, 291–303.
