Iron silicon, also known as ferrosilicon, is a type of ferroalloy, the silicon iron main components are iron and silicon . Adding ferro silicon to cast iron can improve the organizational structure of cast iron, improve machine performance and corrosion resistance. In addition,it can also reduce the liquid temperature and surface tension of cast iron, promote fluidity, and facilitate casting formation.
Graphitization mechanism of silicon iron
Adding silicon iron in casting iron, then Reacts with the carbon in the iron, and The generated SiC decomposes during the rapid cooling process, Producing a large number of free carbon atoms, and promoting the formation and spheroidization of Graphite in Cast Iron. In other words, the carbon atoms of the silicon iron can adsorption carbon of the iron, then produces SiC(silicon carbide).
SiC can decompose during rapid cooling, producing a large number of carbon atoms and silicon atoms. Free carbon atoms can form original graphite nuclei, and due to the presence of silicon carbide, the diffusion rate of carbon can be controlled, making the original graphite nuclei spherical, thus forming a ductile iron structure.
How to control the amount of ferrosilicon added in cast iron
the Addition amount of silicon iron in the casting rion has a large impact for the Properties of cast iron and graphitization effect, Increased brittleness of cast iron if the adding amount Too large and imperfect graphite spheroidization ,and influence on the machinability of cast iron. so usually it has a good effect if the adding amount of silicon iron between the 1% and 3%.
So can ferrosilicon be added to cast iron?
There is no doubt that ferrosilicon can be used in cast iron, and it also plays an important role. It can improve the hardness of cast iron and promote the formation of graphitization of cast iron. However, the specific amount of ferrosilicon added needs to be added according to the actual situation.