Critical pitting temperature dependence of 2205 duplex stainless steel on dichromate ion concentration in chloride medium

In this study, influence of various concentrations of dichromate (Cr2O72-) and chloride ions on critical pitting temperature (CPT) of duplex stainless steel 2205 (DSS 2205) is investigated by employing potentio-dynamic and potentiostatic CPT measurement methods. Potentiostatic results indicate that by adding 0.01 M Cr2O72- to 0.1 M NaCl solution the CPT raised by 12 degrees C. Based on potentiodynamic CPT measurements in the solution of (Cr2O72-)/(Cl-) ratio equal to one for solutions containing 0.1 M NaCl + 0.1 M Cr2O72- and 0.01 M NaCl + 0.01 M Cr2O72-, no CPT was detected up to 75 degrees C. (C) 2011 Elsevier Ltd. All rights reserved.