A comparative study of critical pitting temperature (CPT) of stainless steels by electrochemical impedance spectroscopy (EIS), potentiodynamic and potentiostatic techniques

摘要

In this study critical pitting temperature (CPT) of two stainless steels is compared using EIS, potentiodynamic and potentiostatic techniques. Two types of stainless steels including DSS2205 and 20Cr-28Ni were chosen. EIS measurements were carried at anodic potential of 600 mV/SCE and the results were compared with those of potentiodynamic and potentiostatic polarisations. The results revealed that the CPT of DSS2205 and 20Cr-28Ni was between 45-55℃ and 35-45℃ in potentiodynamic polarisation, respectively. It was 60 and 55℃ for potentiostatic method and between 55-60℃ and 45-55℃ in EIS method for DSS2205 and 20Cr-28Ni, respectively.