Electrochemical potentiodynamic reactivation (EPR), potentiodynamic polarization curve and electrochemical impedance spectroscopy (EIS) methods were applied to investigate the intergranular corrosion and the pitting corrosion behaviors of 2507 duplex stainless steel (SAF2507), and the composition of the passive film formed on the corrosive surface of SAF2507 was studied by using the X-ray photoelectron spectrometer (XPS) analysis. The results show that the reactivation rate (Ra) of SAF2507 is 0.68%, which exhibits good intergranular corrosion resistance. The results of potentiodynamic polarization curve, and EIS show that the surface of SAF2507 can engender passivation phenomenon after polarization, the passivation range is -0.5-0.6V, and the charge transfer resistance is 1.389×104Ω·cm2, which shows better pitting corrosion resistance. XPS demonstrates that the composition of the passive film in 5g/L NaClO solution is mainly composed of oxides and hydrogen oxygen compounds of Cr and Fe. Meanwhile, the corrosion mechanism of SAF2507 was further explored.
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