Abstract
We studied on the inhibitive effect of sodium hexametaphosphate against the corrosion of steel in the presence of bivalent metallic ion such as Ca++, Zn++, Ni++, Cd++, etc. The experiment is a batch test, using the solution containing 100ppm NaCl. The inhibitive action was found to be much influenced by the ratio of metallic ion to sodium hexametaphosphate and the optimum ratio of Ca++, Zn++ and Ni++ to be 50, 25 and 60 parts respectively to 100 parts of sodium hexametaphosphate. The best inhibition is gained with the concentration of sodium hexametaphosphate between 75ppm and 100ppm, and with pH range from 6 to 9. We studied also on the influence of temperature.
