Effect of chloride and sulfate ions in simulated boiler water on pitting corrosion behavior of 13Cr steel

The pitting corrosion behavior of 13Cr steel was investigated in simulated boiler waters containing chloride ions (Cl-) and sulfate ions (SO42-) using potentiodynamic and potentiostatic polarization tests in addition to pit morphology analysis. The presence of 100 ppm cl(-) in the water caused pitting corrosion of the steel. Pit initiation was inhibited by the addition of 50 ppm or 100 ppm SO42- into the water containing 100 ppm Cl-. Pit growth was also suppressed by the presence of 50 ppm SO42- in the water with 100 ppm Cl-; however, it was conversely promoted in the presence of 100 ppm SO42-. (C) 2015 Elsevier Ltd. All rights reserved.