At present, magnesium anode materials are generally used to protect metal structures in high resistivity soil and fresh water. Magnesium is a common sacrificial anode material in electrochemical cathodic protection engineering, which has the characteristics of high chemical activity, negative electrode potential and high driving voltage. At the same time, it is difficult to form an effective protective film on the surface of magnesium alloy. Therefore, in water medium, the driving force of micro corrosion cell on magnesium surface is large, the protective film is easy to dissolve, the self corrosion of magnesium is very strong, and hydrogen evolution reaction occurs in the cathode.
There are three kinds of magnesium based sacrificial anodes: pure magnesium, magnesium manganese alloy and magnesium aluminum zinc manganese alloy. Their common characteristics are low density, large theoretical capacitance, low negative potential, low polarizability and high driving voltage to steel. It is suitable for the protection of metal composition in high resistivity soil and fresh water.
Magnesium can provide effective underground pipeline cathodic protection, savings, refineries, power plants, sewage treatment plants, buildings, oil well casings and other facilities. It is suitable for areas where the resistivity of the surface soil is very high, or even if the resistivity is relatively low, the coating is shallow and its location is high and the resistance is low. Under these conditions, large shallow buried anodes are required and far away from the structure to obtain a sufficiently low ground wire.
However, deep formations must have sufficient low resistivity to fit deep well anodes. When the appropriate voltage is applied, the magnesium anode can produce a certain current compared with the surface soil. When the anode is installed in the deep formation with low resistivity, a very uniform structure current distribution can be obtained. Even if the surface soil is completely suitable for the design of shallow anode ground bed, the structure of magnesium anode is suitable for dense area. Because it is difficult to arrange the shallow buried anode, it can only be arranged far away from the pipeline and other structures.
Shandong Linyi Bosi conductive materials Co., Ltd. is a high-tech enterprise specializing in the production of MMO flexible anode, conductive polymer flexible anode and titanium coated anode, mainly providing cathodic protection technology, engineering design, installation and technical services.
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