The synergistic effect of molybdate with zinc for the effective inhibition of corrosion of mild steel

摘要

ZINC IONS, produced by the electrolytic dissolution of zinc metal rods, exhibited excellent inhibition efficiency, together with the synergistic combination of molybdate and nitrite, This system requires lesser quantities of molybdate and nitrite individually, when compared with the normal amount, generally claimed to be the optimum. Long-term OCP measurements indicated that effective passivation occurs within four days of immersion. The passive layer thus formed on the metal surface retained its strength for few more weeks even after it was transferred into a depleted inhibitor solution. The possible mechanism of passivation is also discussed in detail, based on FTIR spectral evidence.