Conductivity as a New Monitoring Technique for Zinc Metal Corrosion and Corrosion Processes

The electrical conductivity method was successfully applied to monitor the corrosion and corrosion inhibition processes of zinc metal. Measurements of electrical conductivity at 20.0 oC of three different corrosive solutions (NaCl, HCl and NaOH) were performed with two different concentrations (0.10 and 1.00 M) containing zinc sheets in the absence and presence of four different concentrations of sodium lignosulfonate (1.0, 5.0, 10.0, and 20.0 mM). The analysis of curves that illustrates the changes in electrical conductivity of these solutions provides qualitative information about the strength of corrosion as well as the extent of corrosion inhibition behavior. The results obtained from electrical conductivity measurements revealed that sodium lignosulfonate was an effective corrosion inhibitor in acidic medium (for both 0.10 and 1.00 M HCl) in which it converted into lignosulfonic acid, but was less effective in salt and alkaline media.