High Silicon Corrosion-resistant Cast Iron (GB/T8491-1987)
High silicon corrosion-resistant cast iron is an alloy of iron-based alloys that exhibit superior corrosion resistance to other traditional cast irons such as gray iron or ductile iron. It is typically used for applications where corrosive environments are present, for example, sea water, chemical processing, sewage treatment and pollution control. High silicon corrosion-resistant cast iron is characterized by its high silicon and >2.5% chromium content. The addition of chromium improves corrosion resistance by forming a protective chromium oxide layer on the surface of the material.
High silicon corrosion-resistant cast iron was initially developed in China in the late 1980s, based on fundamental research by the Chinese Academy of Sciences related to developing a corrosion-resistant cast iron with superior corrosion resistance and wear-resistance properties. It was formally standardized as GB/T8491-1987 for production and utilization in 1988.
High silicon corrosion-resistant cast iron has become increasingly popular in a broad range of industrial applications due to its improved properties and cost-effectiveness compared to other cast irons. Its superior wear-resistance properties, high tensile strength and machinability makes it well-suited for the production of components that are subject to high wear, such as valve bodies, impellers and other wear components.
The manufacture of high silicon corrosion-resistant cast iron involves the use of specialised moulds that are designed to distribute the high levels of silicon and chromium evenly throughout the material. The composition of the material is closely monitored during production to ensure that the correct balance of alloying elements is achieved.
When selecting high silicon corrosion-resistant cast iron for a given application, it is important to consider the operating environment, temperature and loading conditions in order to ensure that the desired properties are met. The material should also be properly heat-treated before use, to ensure the maximum corrosion resistance and wear-resistance.
High silicon corrosion-resistant cast iron is a cost-effective and versatile material for a wide range of industrial applications where corrosion resistance is important. Its mechanical and thermal properties, combined with its easy machinability and high wear-resistance, make it a viable option over other more expensive materials in certain applications.
