Types of Graphite Electrodes.
Electric arc steelmaking furnaces are generally categorized into three types: regular power (RP), high power (HP), and ultra-high power (UHP). Corresponding to these power levels, graphite electrodes are also classified into three types: regular power (RP grade), high power (HP grade), and ultra-high power (UHP grade). Nominal electrode diameters range from 75 mm to 700 mm. HP and UHP graphite electrodes possess superior physicochemical properties compared to RP electrodes, such as lower electrical resistivity, higher bulk density, greater mechanical strength, a lower coefficient of linear expansion, and excellent oxidation resistance.
Selection of Graphite Electrodes for AC Electric Arc Steelmaking Furnaces.
Graphite electrodes should be selected to match the power level of the electric furnace; for instance, high-power furnaces require high-power electrodes. Selection criteria regarding electrode diameter also vary by furnace power: generally, RP electrodes with diameters of 75–500 mm are chosen for regular power furnaces; HP electrodes with diameters exceeding 300 mm are selected for high-power furnaces; and UHP electrodes with diameters exceeding 400 mm are used for ultra-high power furnaces