THE COEFFICIENT Γ IS THE QUANTITATIVE CHARACTERISTIC OF THE ACTIVATING OR INHIBITING PROPERTIES OF INORGANIC OXIDIZING AGENT OF THE TYPE MEO_X~(Z-) (CHROMATE, VANADATE, TUNGSTATE, MOLYBDATE, PERTECHENTATES, NITRITE AND PEROXIDE COMPOUNDS)

摘要

Inorganic oxidizing agents of the type MeO_x~( -z) such as Chromate, Vanadate, Tungstate, and Molybdate... etc. are widely used as corrosion inhibitor. In non acidic solution these oxidizing agent are reduced on the surface of the metal according to OX + m e + p H_2O ------ Red + n OH~- In which γ = (n-m)/m. The purpose of this publication is to show that for many metals the value of γ for any oxidizing agent determines the possibility of that oxidizing agent being an inhibitor or activator for the corrosion process. The inhibition efficiency for other ions such as Pertecnetate and Tellurate which have not been extensively studied can be predicted. A mathematical equation was derived to express the relationship among the concentration of oxidizing agent, degree of retardation of the corrosion process I cor/I cor 0 (ratio of corrosion current in the solution containing inhibitor to the base solution) , ionic strength of the solution and the coefficient γ. The validity of γ and the mathematical equation were verified by many experimental works on various metals such as zinc, aluminum and steel. All the above research works are based on the published research works of Prof. Mikhailoviskii (from 1979 till 1998) from the Russian Academy of Science.