Synergistic inhibition effect of metal cations and tolyltriazole on copper in industrial cooling system

Abstract

Metal cations, commonly present in industrial cooling water, was found to have certain effect on the corrosion inhibition of copper by tolyltriazole (TTA). Based on the investigation through electrochemistry, immersion test and in-depth analysis, Ca²⁺, Zn²⁺ and Mg²⁺ all show synergistic effect with TTA, with synergistic factor ranging from 1.76 to 15.1. Zn²⁺ was found to incorporate homogeneously onto the surface, while Ca²⁺ and Mg²⁺ precipitate locally and show better resistance to pitting. In summary, the presence of such metal cations in industrial cooling water is rather positive than a concern from the corrosion inhibition perspective.