Effect of temperature, chloride ion and pH on the crevice corrosion behavior of SAF 2205 duplex stainless steel in chloride solutions

An investigation was conducted to examine the crevice corrosion behaviors for SAF 2205 duplex stainless steel in NaCl solutions by using potentiostatic critical crevice temperature measurement. Potentiodynamic polarization technique was comparably used to study the electrochemical behavior. The influence of temperature, chloride concentration and pH on the critical crevice temperature and electrochemical behavior in NaCl solutions was studied. The critical crevice temperature of SAF 2205 DSS in 4% NaCl solution was about 28 A degrees C. The critical crevice temperature decreased linearly with an increase in log [Cl-]. A maximum critical crevice temperature was found in 4% NaCl solutions at pH 8.5. The influence of the duplex microstructure on attack development and morphology was analyzed by scanning electron microscope.