When using carburizing agent for casting, the amount of scrap steel will be greatly increased, and a large amount of carburizing agent needs to be added to supplement carbon. Here are some precautions.
1. Superheat temperature of molten iron: the large amount of absorption of carburizing agent is generally above 1420 degrees, so the superheat temperature of molten iron can not be too low, and it is better to have a temperature of 1450-1550 degrees. At this time, the carburizer and its various added auxiliary materials are fully decomposed and absorbed.
2. Timing: the absorption rate of the carburizer is directly proportional to the extension of time. Generally, the carburizer that has been graphitized at high temperature can be fully absorbed after being kept at high temperature for about 10 minutes.
3. Stirring degree of molten iron: the contact surface area between carburizer and molten iron increases. The absorption speed is accelerated and the absorption rate is increased. Therefore, under normal circumstances, the carburizing agent should be added before smelting, which will have a better effect than adding it on the surface of molten iron or hanging ladle.