Influence of sensitization on passive films in AISI 2205 duplex stainless steel

• Passivation property of 2205 steel decreased due to increased passivation potential.
• Current peak at 0.6 VSCE for sensitized 2205 steel increased doping concentration.
• Chromium-depleted regions facilitated occurrence of dissolving of Cr.

The effect of sensitization at 600 °C on passive films on the surface of 2205 duplex stainless steel was investigated by the double loop electrochemical potentiokinetic reactivation technique, potentiodynamic polarization curves, electrochemical impedance spectroscopy and X-ray Photoelectron Spectroscopy. With the increasing of the passivation potential, the passivation property of the solid solution annealed sample decreased. Moreover, the corrosion resistance of the passive film on sensitized sample was lower than that on solid solution annealed sample, especially at 0.6 VSCE. These results were supported by X-ray Photoelectron Spectroscopy and Mott–Schottky analyses.