Corrosion behavior of 2205 duplex stainless steel in NaCl solutions containing sulfide ions

The corrosion behavior of 2205 duplex stainless steel (DSS) in sulfide-containing NaCl solutions at different pH values are investigated. In 0.8 g/L NaCl solutions, the 2205 DSS pitting corrosion resistance increased with Na2S addition. The pH has significant effects on the corrosion mechanism of 2205 DSS in a 35 g/L NaCl solution with sulfide. In 35 g/L NaCl solutions, addition of Na2S can improve pitting resistance of 2205 DSS at pH 11.5, but the Na2S addition promotes pitting corrosion at pH 9, 7 and 4. At pH 7, the pitting corrosion resistance of 2205 DSS is the worst with sulfide.