Alloy cast iron with high corrosion resistance in some media can be obtained by adding certain alloying elements into cast iron. High silicon cast iron anode is one of the most widely used, a series of alloy cast iron anode containing 10% ~ 16% silicon is called high silicon cast iron anode.
PERFORMANCE OF HIGH SILICON CAST IRON ANODES
strong corrosion resistance, high silicon cast iron anode with silicon content of more than 14% has good corrosion resistance, because silicon forms a protective film composed of SiO2 on the surface of cast iron. If the medium can destroy the SiO2 film, the high silicon cast iron anode is not corrosion resistant in this medium.
Generally speaking, the high silicon iron anode has excellent corrosion resistance in oxidizing media and some reducing acids. It can withstand the corrosion of nitric acid, sulfuric acid, acetic acid, hydrochloric acid, fatty acid and many other media at various temperatures and concentrations. It is not resistant to high temperature hydrochloric acid, sulfite, hydrofluoric acid, halogen, caustic solution and molten alkali and other media corrosion. The reason of corrosion resistance is that the SiO2 protective film on the surface forms soluble Na2O3 under the action of caustic alkali, and forms gaseous SiF4 under the action of hydrofluoric acid, so that the protective film is destroyed.
ADVANTAGES OF HIGH SILICON CAST IRON ANODES
high silicon cast iron anodes is in order to ensure the quality of cathode protection engineering site construction and simplify the process of site construction and development, has the consumption rate is low, construction is convenient quickly, and the advantages of small ground resistance, the original operation in the factory in construction field, effectively ensure the installation quality of anode ground bed.