Electrochemical Corrosion Behavior of Alloy 600 in Chloride-Sulfate Solutions

Chloride ions have been known to be one of the main causes for pitting corrosion of Alloy 600 steam generator materials. Furthermore, they accelerate the corrosion rates of low alloy steels such as tube sheet and tube support plate, resulting in tube denting. Sulfate ions were also detected on the surface of stress corrosion cracks, intergranular attack and pitting in the secondary side of steam generator tubes. In addition, chloride and sulfate ions are the major cations to determine a molar ratio index for managing the secondary water chemistry. In this work, corrosion behavior of Alloy 600 was studied using a potentiodynamic technique in chloride sulfate solutions at room temperature