Effect of Molybdate Ion on the Repassivation Kinetics of Iron in Solutions Containing Chloride Ions

Abstract

The effect of molybdate ions on the repassivation kinetics of iron has been studied by measuring anodic current transients following in situ film removal by abrasion. In solutions containing both chloride and molybdate ions, it was found that although pits initiate, they do not propagate when molybdate ions are present. Thermodynamic data and electron microprobe analysis suggest that molybdenum improves localized corrosion resistance by forming an insoluble molybdate compound.