The Corrosion Behavior of High-Alloy CrMnNi Steels—A Research Work on Electrochemical Degradation in Salt- and Acid-Containing Environments

Abstract

The electrochemical corrosion behavior of high-alloy cast steelsas well as of steel/ceramic composites was analyzed by conventional polarization, electrochemical impedance and long term-outdoor exposure tests in sulfuric acid and chloride containing solutions. Additionally, for the determination of corrosion initiation processes and its subsequent implications, potentiodynamic polarization and electrochemical noise were combined with the acoustic emission technique. The results of these studies show that several corrosion mechanisms occur simultaneously when the surface is potentiodynamically stressed, and that pitting corrosion starts with a specific time-shift to its initiation at the surface.