Effect of isothermal aging on the pitting corrosion resistance of UNS S82441 duplex stainless steel based on electrochemical detection

The effect of isothermal aging at 700 degrees C for various times on the pitting corrosion behavior of UNS S82441 duplex stainless steel was investigated using a combination of potentiodynamic polarization and potentiostatic critical pitting temperature techniques. The results show that the austenite phase of the as-annealed specimen is susceptible to pitting. With increasing aging time, the resistance of test specimens to pitting corrosion decreases. Additionally, pitting transfers from the austenite phase into chromium-depleted zones. Finally, the corrosion evolves from pitting corrosion into general corrosion as the holding time extends to 48 h. (C) 2015 Elsevier Ltd. All rights reserved.