Effect of Alloy Element Additions on the Pitting Corrosion of Mild Steel Available to Purchase

A potentiometer which measures localized corrosion is used to study the effects of small additions of the alloying elements nickel, copper, aluminum, and chromium in mild steel. These elements vary the potentials and therefore the patterns of corrosion and the corrosion rate. It has been shown that chromium considerably reduced the amount of corrosion but large localized potentials develop. Aluminum develops a similar pattern, but the potentials are less, while nickel and copper promote more generalized pitting which is less severe. This is a preliminary study in an effort to develop better marine grade steels.