Electrochemical Noise Measurements On Mild and 12%Cr Steel In Chloride Solution

Electrochemical noise monitoring is concerned with the measurement of random fluctuations in potential and current occurring during corrosion processes. Electrochemical potential and current noise v. time records have characteristic features related to the mechanism of corrosive attack and can be used to identify the onset of localised corrosion such as pitting. Noise trials were carried out on mild and 12%Cr steels in a synthetic mine water containing high levels of chlorides and sulphates. Electrochemical noise can distinguish between pitting on a 12%Cr steel and general corrosion on mild steel. Current noise is extremely sensitive and capable of detecting pit initiation.