In order to avoid the slow melting and heating time of graphite carburizer, scrap steel and carburizer are added in batches during the batching process, and the melting time of each batch of furnace materials is about 15 minutes. In the early stage of chemical feeding, low power is used to avoid the burning loss of graphite carburizer caused by excessive temperature. In the later stage, the temperature rises rapidly after the molten iron paste is formed. It cannot be effectively combined with molten iron and the temperature is too high, resulting in serious burning loss. Similarly, the amount added in the last time should be relatively small, so as to avoid adding graphite carburizer into molten iron in large quantities, resulting in incomplete absorption of graphite carburizer in molten iron and production delay.
The absorption rate of graphite carburizing agent can be effectively improved by combining mechanical mixing with manpower. The specific gravity of graphite carburizing agent is small. Manual mixing can reduce the burning loss of graphite carburizing agent due to floating on the surface. Mixing can also reduce the heat preservation time of graphite carburizing and shorten the generation cycle. However, if the stirring time is too long, the burning loss of the carburizer will be serious.
When selecting graphite carburizers, we should choose graphite carburizers with moderate particle size and high density, because the denser and larger the particle size of graphite carburizers, the harder it is to absorb. In order to achieve a higher absorption rate of graphite carburizers and prevent graphite carburizers from being oxidized at high temperature for a long time, the power in the early stage of the melting process should be small enough to prolong the heating time of graphite carburizers to improve the absorption rate.