In this study application of two electrochemical methods (Potentiodynamic and potentiostatic polarization) for measuring critical pitting temperature (CPT) of DSS2205 alloy in 0.1M NaCl solution was investigated. In potentiodynamic test CPT was measured by anodic polarization of DSS2205 at temperatures between 25 to 75ºC and considering CPT as the temperature which a transition from transpassive corrosion to pitting corrosion occurred. In potentiostatic method, the specimen was polarized at anodic potential of 750 mV with respect to open circuit potential while temperature was increased by the rate of 0.6ºC/min. The CPT was defined as the temperature in which the current density associated with the pitting corrosion reached 100μA/cm2. The result showed CPT between 50 and 55ºC in potentiodynamic method and 59ºC in potentiostatic measurement. This difference is due to the fact that the passive layer in potentiostatic method extends and modifies during applied potential; therefore passivity breakdown occurs in higher temperature. Keywords:

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