Evaluating localised corrosion intensity using the wire beam electrode

Highlights: ► A new parameter namely the localised corrosion intensity index. ► A method for quantifying the degree of localisation of corrosion. ► A method for evaluating the effects of factors affecting the intensity of localised corrosion. ► Moderating localised corrosion intensity by promoting random distribution of anodic sites. - Abstract: The intensity of localised corrosion of steel in the Evans solution has been evaluated by means of an electrochemically integrated multi-electrode array namely the wire beam electrode. A new parameter namely the localised corrosion intensity index (LCII) has been employed to quantify the degree of localisation of corrosion and the effect of pH alteration on the intensity of localised corrosion. A major variation in the LCII has been found to indicate a change in corrosion mechanism. In a typical experiment, the LCII dropped dramatically from approximately 1 to 0.02 when a pH modifier was added to the Evans solution, leading to the change of corrosion mechanism from highly localised pitting corrosion to general or uniform corrosion.