Influence of Mass Ratio of Ni to Cu and Si Content on Electrochemical Corrosion Behavior of Weathering Steel Used in Marine Environment

Electrochemical techniques were employed to fastly investigate the electrochemical corrosion behavior of weathering steels used in marine environment in 3.5% NaCl solution. The results indicate that with the increase of mass ratio of Ni in Cu (Ni/Cu ratio), the corrosion current density of these steels was always reduced, free corrosion potential shifted in positive direction in low and middle Si content (about 0.6wt% and 0.9wt%), but hardly changed in high Si content (about 1.2wt%). The effects of Ni/Cu ratio and Si content on corrosion resistance of these steels were interactive. The corrosion resistance of test steels was bad at low Ni/Cu ratio, or in high Si content. Only when the Si content was about 0.9 wt% and Ni/Cu ratio was 0.50, the steels had the best corrosion resistance.