The traditional smelting method is similar to cupola smelting, which uses pig iron, recycled materials, scrap steel, ferroalloy, etc. as metal furnace materials; The new synthetic cast iron production process uses scrap steel as furnace charge, and uses carburizing agent to adjust the carbon equivalent of molten iron. The latter is easier to ensure high-quality molten iron, and greatly reduces the cost by using less or replacing pig iron with scrap steel. There are many sources and forms of carburizers, and the price varies greatly according to their processing technology and composition.
First, the stirring degree of molten iron increases the contact surface area between the carburizer and molten iron. The absorption rate is fast and high. Therefore, under normal circumstances, the carburizing agent should be added before smelting, and the effect of adding on the surface of molten iron or ladle is very ideal.
In addition, the superheat temperature of molten iron is generally more than 1420 degrees, so the superheat temperature of molten iron cannot be too low, generally 1500-1550 degrees. At this time, the carburizer decomposes on its various chemical substrates, and the mechanical properties of the castings can reach the best.
Finally, it is time to grasp. The absorption rate of the carburizing agent is proportional to the extension of time. Generally, it can be fully absorbed when it is kept at high temperature for about 10 minutes.