Inhibition by Magnetic Fields of the Corrosion of Iron in Sodium Chloride Solution
Atsushi Chiba, Nobuaki Tanaka, Seiji Ueno, Tadahiko Ogawa
The corrosion of iron plate was inhibited in 0.01-20% sodium chloride aqueous solutions with magnetic field. The corrosion was inhibited with increasing of magnetic flux density. Magnetic field accelerated the dissolution rate and solubility of oxygen gas. Magnetic field had some accelerated the catholic reaction (O2+4H++4Fe2+→4Fe3++2H2O), however magnetic field had more inhibited the anodic reaction (Fe→Fe2++2e-). Reactions (Fe2++8γ-FeOOH+ 2e-→3Fe3O4+4H2O and Fe2++OH-→FeOH+→Fe3O4) were activated with magnetic field. The white sediment on iron plate was changed to Fe3O4. A Fe3O4 was attracted by a magnetic force, and was deposited on surface. The corrosion was inhibited as the surface of iron was passivity. It was concluded that the attraction effect of Fe3O4 by a magnet and the increasing of formation rate of Fe3O4 were main effects with magnetic field in initial period.