1. Because the corrosion of the metal provides protection to the original corrosion battery and accelerates the corrosion of its own, it is called the sacrifice anode. The sacrificial anode material should satisfy this requirement: it should have sufficient negative potential and be stable.

The sacrificialanode is made of a metallicialmaterial with a relatively negative potential. When it is connected with the protected pipeline, it preferently dissociates itself and thus inhibits the corrosion of the pipeline, so it is called the sacrificialanode. The sacrificial anode should have enough negative stable potential to maintain a large enough driving voltage, with a large theoretical electricity generation, and a high and stable current efficiency.

3. The metal or alloy with a moderate negative potential is called the sacrificial anode. Considering the explosive risk of the original oil and gas itself to avoid stray current, the applied current corrosion prevention method in the crude oil storage tank is not reliable.

The three ideal anode materials are magnesium, aluminum and zinc, whose corrosion potential in natural environment reaches -10V(relative to Cu, CuSO4, the same below).