The Chemical Polishing of Mild Steel by Hydrogen Peroxide—Oxalic Acid Mixtures

PEROXIDE-INHIBITED DECONTAMINATION SOLUTIONS FOR CARBON STEEL AND OTHER METALS IN THE GAS-COOLED REACTOR PROGRAM. Progress Report, November 1959-July 1962

“…The study of the passivation of carbon steel by hydrogen peroxide i n oxalate salt solutions at elevated temperature, i n the present ORNL work, may i n art be considered a further development of the work of Marshall, Hickling, and Rostron.%, 26 Their electrode-potential method, slightly modified, was a useful tool i n the evaluation of the peroxide concentration necessary to maintain corrosion passivity with various formulations and temperatures. Although Schumb et a1.18 warn that the inhibitive behavior --of hydrogen peroxide on iron surfaces i s capricious and should not lead t o consideration of its use i n practice, i t now appears that safe use can be made of this property i n oxalate formulations at controlled temperature and pH for decontamination purposes.…”

“…A preferred method which was adopted was the determination of the peroxide concentration which induced passivity, as shown by the electrode-potential method. 26 The metal was sanded clean, dipped into the solution under test, and connected to one terminal of a Beckman model G pH meter, set for millivolt readings. The other terminal was connected to a standard calomel electrode i n a small beaker of the solution at room temperature, which was electrically continuous, via a liquid bridge, with the heated solution.…”