Synergistic corrosion inhibition on galvanically coupled metallic materials

The present paper brings report on a newly observed effect of synergistic corrosion inhibition of galvanically coupled metals by the combination of inhibitors. 1,2,3-Benzotriazole and Ce(NO3)3 were investigated here as a synergistic inhibiting mixture for Zn + Fe model galvanic couple. Microelectrode array cell specifically designed for investigation of inhibition processes on multi-material galvanic couples was applied for the first time utilising scanning vibrating electrode technique (SVET) as method of galvanic current quantification. The obtained results demonstrate a strong potential of inhibitor combinations for high efficiency suppression of corrosion processes when different inhibition mechanisms are employed at the same time. This effect is observed especially in the cases when the same inhibitor combination does not show synergy on the uncoupled single Zn and Fe metals.

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► Highly synergistic combination of corrosion inhibitors for Zn-Fe galvanic couple.
► SVET was applied for galvanic corrosion activity quantification.
► Selective action of BTA at anodic and Ce(NO3) at cathodic site of Zn + Fe couple.