Graphitization Influence Of Unmelted Particles in Carburizers

In the molten iron, in addition to the dissolved carbon, the recarburizer also has residual, undissolved carbon in the form of graphite, which is entrained in the agitated liquid stream in granular form. Most of the unmelted and coarse graphite particles are suspended on the molten iron surface near the furnace wall when electrified, and a part of them are attached to the middle of the furnace wall, which is equivalent to a stirring dead angle. At this time, once the electricity is stopped, these coarse graphite particles will be slowly suspended due to buoyancy. In the process of graphite melting, extremely tiny particles beyond the observation range of an optical microscope can be suspended in the molten iron not only when the electricity is energized, but even when the electricity is stopped.

According to reports, the closer to the material that forms the eutectic nucleus, even if the crystallinity of the added graphite and eutectic graphite is somewhat different, compared with other substances that can be inferred to form the graphite nucleus, the degree of coupling is bound to be larger. From this point of view, it can be considered that the suspended fine graphite particles are conducive to the formation of graphite cores, which can prevent the cast iron from being overcooled and whitened.