Abstract
Hydrogen entry behaviour into coated steels under the aqueous H2S environments and additives to inhibit it were studied.
The linear correlation was observed between hydrogen permeation current detected on the rear side and corrosion potentials on the painted side except for the initial stage when the coated steel panel was contacted to the hydrogen sulfide environment.
The corrosion potentials shifted to noble one and the cathodic current was found to increase when V2O5 was added in Ager-gel on the steels. This result indicates that the noble shift of corrosion potentials is due to the depolarization of the cathodic reaction by the addition of V2O5.
The corrosion loss of the steel was regardless of V2O5. The generation of hydrogen blister was, however, observed to be inhibited greatly by V2O5. This leads to the assumption that the inhibitive effect of V2O5 on hydrogen entry is not based on corrosion currents but on the noble shift of corrosion potentials.
