Macrocell Corrosion of Q235 Steel in Polluted Soils due to the Difference of Oxygen Concentration

The macrocell corrosion of Q235 steel in polluted soils due to the difference of oxygen concentration was studied using weight loss and electrochemical impedance spectroscopy (EIS).It was found that Q235 steel in clay was an anode and in sand was a cathode when Q235 steel formed a macrocell between clay and sand.Along with test going,the corrosion rate of Q235 steel,which was buried in clay by natural style,became slow,but the anode of macrocell in clay kept a rapid corrosion rate.The corrosion rate of anode in clay was 2.15 times of that in natural condition.When the area ratio of cathode to anode being 15∶1,the corrosion ratio of anode in clay was nearly 2 times of that in condition of the area ratio of cathode to anode being 1∶1.