Influence of Ferric Ions on Corrosion Behavior of A508III Low Alloy Steel in Boric Acid Solutions

The influence of ferric ions on corrosion and electrochemical behavior of A508III low alloy steel in boric acid solutions at 25 ℃ was investigated using electrochemical measurements and weight loss measurements. Increasing Fe3+ concentration in boric acid solution decreased the electrochemical impedance value and the linear polarization resistance,increased the current densities of anodic and cathodic polarization,and significantly increased the corrosion rate. Adding boric acid into ferric ion solutions had no any significant effect on electrochemical behavior and corrosion rate of the steel. Ferric ion would accelerate the corrosion of A508III steel in boric acid solution. The effect of boric acid concentration on corrosion of A508III was not significant if the concentration of ferric ion in solutions was considerably high.