Overview
It is made of quartz sand, petroleum coke (or coal char), wood chips (which need to add salt when producing green silicon carbide) and so on. Silicon carbide is also a rare mineral in nature, Moissanite. Silicon carbide is also known as carbon silica. Among the non-oxide high-tech refractory raw materials such as C, N and B, silicon carbide is the most widely used and economical one, and it can be called gold steel sand or refractory sand. At present, China's industrial production of silicon carbide is divided into black silicon carbide and green silicon carbide, both hexagonal crystals, specific gravity of 3.20 ~ 3.25, microhardness of 2840 ~ 3320kg / mm2.
Function and characteristics
Silicon carbide has deoxidation, carbonization, silicon enhancement, purification of molten iron and inoculation. In the smelting, the graphite core is increased, the number of graphite balls of the ductile iron is increased, the graphite form of the gray iron is improved, the degree of supercooling of the molten iron is lowered, and the service life of the lining is prolonged.
Advantages of silicon carbide:
1. Prevent precipitation of carbides, increase the amount of ferrite, and reduce the tendency of white mouth;
2. Significantly improve cutting performance and improve mechanical properties;
3. Increase liquidity to stabilize the molten iron composition and prevent segregation;
4, reduce the wall thickness sensitivity, make the tissue dense, the cutting surface is smooth;
5. Enhance the ability of graphite nucleation and increase the graphite core;
6. It is a strong deoxidizer for ductile iron, which can reduce the amount of spheroidizing agent to increase the spheroidization rate;
7. Eliminate the oxidation of iron liquid, reduce the oxidation of the furnace wall, and extend the life of the furnace wall;
8. Enhanced deoxidation and purification of molten iron;
9. In the case of gray iron, increase the A-type graphite, reduce the D-type graphite, the number of eutectic and spheroids is obviously improved, and the tensile strength is increased by 10%-30%.