Galvanic Corrosion Behavior of Copper–Drawn Steel for Grounding Grids in the Acidic Red Soil Simulated Solution

The influence of pH and metallographic structure on the corrosion behavior of copper–drawn steel is studied with the simulated system. The effect of pH on the corrosion behavior of copper–drawn steel has been investigated using open-circuit potential, potentiodynamic polarization, galvanic current measurement, scanning electron microscopy and scanning vibrating electrode technique techniques. The steel is corroded as anode, while the corrosion of copper plate is protected as cathode. All the results revealed that pH and metallographic structure had a significant influence on the corrosion behavior of copper–drawn steel. With the decrease in pH value from 6 to 2.4, the corrosion rate of copper–drawn steel galvanic couple (Cu–Fe GC) obviously increased in the simulated solution of acidic red soil. The electric field formed by the Cu–Fe GC changes the direction of ion migration between the copper and drawn steel electrodes, which impacts the composition and microstructure of corrosion products formed on the electrode surface.