Zinc anode cathodic protection The cathodic protection of zinc anode is in the protection of steel equipment connected to a more electron loss of metal or alloy. Steel gate protection, which is a more reactive metal, such as zinc, attached to the steel gate. In this way, when electrochemical corrosion occurs, it is a more reactive metal than iron that is corroded, and iron is protected. This method is used to prevent corrosion of the hull, etc., by loading a certain amount of zinc at the stern of the ship and below the waterline of the hull. At present, in addition to the protection of steel equipment in seawater or river, electrochemical protection is also applied to prevent cables and oil pipelines. Corrosion of Tangut equipment and chemical equipment, etc. An electrode that protects the coupled cathode by increasing its own corrosion rate. Anode with the outflow of current and gradually consumed, so, called sacrificial anode, this anode consumption fast, installation position and method must be easy to replace, low potential metal materials such as magnesium, magnesium alloy, pure zinc, zinc alloy, aluminum alloy, etc. The main features of zinc anode are surface polarization resistance, high current efficiency, wide material sources and low price. The disadvantage of zinc anode is that compared with iron, the protective potential (-0.85V) excitation voltage is small, only 0.25V, equivalent to 1/3 of magnesium anode, so the application range is narrow. Used in soil, generally very system in ρ< 150Ω·m medium (GB/T 4950). When the soil is wet, it can be expanded to ρ< 30Ω·m(SYJ20 -- 1986).