Experimental studies on the effect of ions and molecules of the type XO4n− upon corrosion of iron and steel are summarized. Measurements of electrode potentials in inhibited solutions and the effect of foreign electrolytes upon these potentials have shown the competitive and reversible nature of the surface state associated with inhibition. Studies with the pertechnetate ion as inhibitor have demonstrated absence of detectable continuing chemical action in the system over a period of more than five years. Passivation by OsO4 is so complete that an iron electrode indicates the thermodynamic potential of the OsIV-OsVIII couple. The Flade potential may be observed on iron electrodes in aerated, inhibited solutions without use of such vigorous passivating agents as HNO3 or anodic polarization. Results are discussed by considering the ways in which presence of an adsorbed inhibitor may affect the kinetics of electrode processes at a metal-solution interface. Specific differences among the XO4n− particles with respect to inhibition may arise from the nature of the electrostatic field exerted by such particles over short distances.
Action of the Inhibitors
G. H. CARTLEDGE—Engaged in fundamental research in the Chemistry Division of the Oak Ridge National Laboratory (operated by Union Carbide Corporation for the U. S. Atomic Energy Commission). He received an AB and AM from Davidson College in 1911, and a PhD in chemistry from the University of Chicago in 1916. From 1920-1931 he was associate professor, professor and director of college work in chemistry at Johns Hopkins University. Dr. Cartledge was head of the department of chemistry at the University of Buffalo 1931-1945 and dean of faculty and and professor of chemistry at King College, 1946-1951. He is the author of textbooks on inorganic and physical chemistry and research papers in the fields of complex compounds and theoretical chemistry in addition to a recent series of papers on inhibitors.
