Effect of Cl^- on Corrosion Behavior of High Nitrogen Stainless Steel in 0.5 mol/L NaOH Solution

The electrochemical behavior of a high nitrogen stainless steel (HNSS) in 0.5 mol/L NaOH solution with different NaCl concentrations was investigated by means of potentiodynamic polarization curves,electrochemical impendence spectrum,current-time transient and Mott-Schottky curves.The results show that the HNSS had good corrosion resistance,and the potentiodynamic polarization curves of the HNSS exhibited anodic passivation in 0.5 mol/L NaOH solution containing Cl^-.The concentration of Cl^- had no remarkable effects on pitting potential.The passive current density of the HNSS increased with the increase of Cl^- concentration.The passive film formed on the surface of the HNSS exhibited n type semiconductor and still had good protection,when the Cl^- concentration increased to 1.00 mol/L.The donar density of passive film increased with the increasing of Cl^- concentration.