According to the crystal structure of carbon in the carburizer, the carburizer can be divided into amorphous state and crystalline state; According to the existing form of carbon atom, it can be divided into graphitized carburizing agent and non graphitized carburizing agent. Graphitized carburizers mainly include graphitized petroleum coke and graphite electrode.
Graphitized petroleum coke carburizer is widely used in the foundry industry. Its production process is the high temperature heat treatment process that the raw material petroleum coke is heated at 2200-2600 ℃ in the graphitization furnace to transform the amorphous disordered layer structure carbon of petroleum coke into three-dimensional ordered graphite crystal, that is, the graphitization process to achieve the graphitization state.
Non graphitized carburizing agents mainly include calcined petroleum coke, coal based carburizing agent and so on. Calcined petroleum coke refers to the fact that petroleum coke is heated at 1200, 1500 ℃ with low treatment temperature and unchanged crystal structure. The main indexes to measure the quality of carburizer are fixed carbon content, sulfur content, volatile content, ash content, nitrogen content and water content. After graphitization at high temperature, the sulfur and nitrogen content of graphitized carburizing agent is much lower than that of non graphitized carburizing agent.
