Prediction and Measurement of Corrosion Rates of Stainless Steel in Concentrated Sulfuric Acid

Stainless steel exhibits unique electrochemical behaviour when exposed to concentrated sulphuric acid. This behaviour can be observed as an oscillation in open-circuit potential between the active and passive states.The transient nature of the corrosion behaviour under these conditions results in a distinct challenge for measuring and predicting corrosion rates. This paper outlines the utilization of both kinetic modeling and electrochemical experimentation to refine the prediction of corrosion rates. The paper also discusses some of the difficulties associated with many traditional electrochemical techniques such as potentiodynamic scans when used for characterizing systems which undergo oscillations in open-circuit potential.

Keywords: Concentrated Sulphuric acid, Stainless steel, Open circuit potential, Oscillations