Effect of temperature change rate on the critical pitting temperature for duplex stainless steel

The effect of temperature change rate on the critical pitting temperature (CPT) for two kinds of duplex stainless steels (DSS, namely UNS S31803 and UNS S32750) in 1 mol L-1 NaCl solution was investigated using the potentiostatic current transient technique. The values of CPT for two DSSs all increased as the temperature change rate (upsilon) increased. A linear relationship between the CPT and the square root of temperature change rate (upsilon(1/2)) was found. Furthermore, deriving from the point defect model (PDM), this particular relationship received theoretical support at low temperature change rates.