The electric arc is the heat source in the electric arc furnace, which determines the thermal conditions in the furnace. Due to the characteristics of the arc itself, it determines the electrical characteristics of the electric arc furnace equipment. This in turn determines all aspects of electric arc furnace steelmaking.

Electric furnace steelmaking​ mainly uses arc heat. In the arc action zone, the temperature is as high as 4000 °C. The smelting process is generally divided into a melting period, an oxidation period and a reduction period. In the furnace, not only an oxidizing atmosphere but also a reducing atmosphere can be created, so the efficiency of dephosphorization and desulfurization is very high.