EIS assessment of critical pitting temperature of 2205 duplex stainless steel in acidified ferric chloride solution

In this study, critical pitting temperature (CPT) of 2205 duplex stainless steel (DSS2205) was assessed using electrochemical impedance spectroscopy (EIS) in ferric chloride solution. In order to verify the results other methods such as ASTM G 48, potentiodynamic and potentiostatic polarisation and zero resistance ammeter (ZRA) were also employed. The results show a strong close relation between the results of this method by those of previous methods. CPT of the alloy is 40 degrees C based on standard method and 44 degrees C, 49 degrees C according to the ZRA and potentiostatic methods. Both potentiodynamic and EIS methods give an almost identical CPT value. (C) 2013 Elsevier Ltd. All rights reserved.