Effect of pH Value on Electrochemical Behavior of High Nitrogen Stainless Steel in NaCl Solution

Abstract

The electrochemical behavior of high nitrogen stainless steel(HNS) in 1 mol/L NaCl solution with different pH values was investigated by means of potentiodynamic polarization curves, electrochemical impendence spectrum and current-time transient curves. The results show that anodic passivation of HNS could occur in alkaline solutions, while the corrosion rate of HNS decreased with the increasing pH value; a porous film might be grown on HNS in neutral NaCl solution due to the companying processes of dissolution and repassivation. In acidic and alkaline NaCl solutions, the formed passive films on HNS exhibit superior protectiveness rather than that in neutral NaCl solution.