There are many coarse hypereutectic graphites in pig iron. This kind of coarse graphite is hereditary, the melting temperature is low, and the coarse graphite is not easy to be eliminated. The coarse graphite is inherited from the liquid state to the solid cast iron structure. On the one hand, it reduces the cast iron. The strength reduces the performance of the material, on the other hand, it weakens the expansion of the graphitized precipitation that should have occurred during the solidification process, and increases the shrinkage tendency during the solidification process of the molten iron.

In cupola smelting, try to reduce the amount of pig iron charge, use carburizer to ensure high carbon equivalent, and relatively increase the amount of scrap steel. In this way, under the condition of high-temperature smelting, carbon with good activity and more significant graphitization can be obtained by carburizing. It is reflected in the casting that the morphology of graphite is better, which is beneficial to improve the mechanical properties, reduce the shrinkage tendency and improve the processing performance.

During electric furnace smelting, high-quality molten iron can be obtained by carburizing with low pig iron consumption or even zero consumption.

In terms of material performance, the mechanical properties of the large proportion of pig iron used in the past are half a grade lower than that of high scrap steel with the same composition. Therefore, the new process of adding carburant smelting is superior to the traditional large proportion of pig iron in terms of cost and product performance.