Carburizer is a follow-up product of black or gray grain (or block) coke or petroleum coke with high carbon content, which can reduce the oxygen content in molten iron and improve the mechanical properties of castings during metal melting. In the new synthetic cast iron smelting process, the amount of scrap steel used has greatly increased. By adding carburetors to adjust the carbon content of the molten iron, production costs have been greatly reduced while ensuring the quality of the molten iron.
2. Types of carburizing agents used for cast iron
According to the crystal structure of carbon in carburetors, they can be divided into amorphous and crystalline states; According to the existence form of carbon atoms, they can be divided into graphitized carburetors and non graphitized carburetors. Graphitized carburants mainly include graphitized petroleum coke and graphite electrode. Graphitized petroleum coke carbon additive is the most widely used in the casting industry. Its production process is to heat the raw material petroleum coke in a graphitizing furnace at 2200-2600 ℃, so that the amorphous disordered layer structure of petroleum coke can be crystallized into three-dimensional ordered graphite crystals. Non graphitized carburants mainly include: calcined petroleum coke, coal based carburants, etc. calcined petroleum coke refers to petroleum coke that has been heated at 1200-1500 ℃ at a low temperature and its crystal structure has not changed. Coal based carburetors are rarely used in electric arc furnace melting due to their high ash and volatile content. The main indicators for measuring the quality of carburetors include fixed carbon content, sulfur content, volatile matter, ash content, nitrogen content, and water content. After high-temperature graphitization treatment, the sulfur and nitrogen content of graphitized carburetors are significantly lower than those of non graphitized carburetors. In short, the higher the fixed carbon, the lower the sulfur and phosphorus structure, and the looser the carbon containing material. The higher the absorption rate during use, the better the effect.