Abstract
Polarization resistance and weight loss of mild steel were measured in 1% sodium chloride solution containing various quantity of sodium silicate as a corrosion inhibitor. The effect of adding a certain kind of metal chloride to the above solution was also investigated.
It was found that the corrosion rate decreases as the polarization resistance increases, and their relation was obtained to be linear on log-log plot. Based upon this relationship, the corrosion rate, including its time variation, can easily be estimated by the measurement of polarization resistance. This method of evaluating the effectiveness of corrosion inhibitors has a superiority such as it can be conducted without taking the specimen out of the solution.
In the course of the present investigation, a considerable increase in the inhibiting effect of sodium silicate was noticed by the presence of either one of Zn++, Mn++ and Ni++ ions. It was also found that there exists a certain weight-ratio to make the inhibiting effect maximum.
