Critical pitting temperature (CPT) assessment of 2205 duplex stainless steel in 0.1 M NaCl at various molybdate concentrations

In this study, the influence of various concentrations of molybdate (MoO42-) on critical pitting temperature (CPT) of duplex stainless steel 2205 (DSS 2205) in 0.1 M NaCl solution has been investigated by employing potentiodynamic and potentiostatic CPT measurements methods. No significant increase in CPT was observed in the presence of 0.0001 and 0.001 M molybdate. However, addition of 0.01 M MoO42- increases 10 °C in CPT and pitting corrosion was not observed in solution containing 0.1 M molybdate up to 85 °C. Potentiostatic CPT measurements showed CPT values of 68 and more than 85 °C in 0.01 and 0.1 M molybdate concentrations, respectively.

Research highlights► Demonstrating beneficial effect of MoO42- on CPT of 2205 DSS. ► A 10 °C increase in CPT was obtained by addition of 0.01 M MoO42-. ► No pitting corrosion detection at the presence of 0.1 M MoO42- up to 85 °C.