Azole, amine, benzoate and nitrate compound mixture as VPI for metals in NaCl and SO₂ environments

Abstract

A variety of tests were performed to evaluate the feasibility of vapour phase corrosion inhibitor’s (VPI’s) application for maintenance and protection of transporting metal articles from corrosion damage. Three types of VPI were evaluated for their inhibition characteristics for mild steel (MS) and copper. Minimum dosage of one g/L is required for protections of both metals. Influence of SO₂ and chloride contamination on inhibitor performance was also investigated. The corrosion behaviour of MS and Cu in sodium chloride (0.005 M NaCl) environment in presence of VPI impregnated and unimpregnated paper has been studied by using weight loss, potentiodynamic polarization and A.C impedance spectroscopic methods. It has been found that 1g L⁻¹ of VPI impregnated on Kraft paper provides nearly 98% inhibition efficiency for mild steel and copper in 0.005 M NaCl environment.