Electric arc furnace steelmaking is to generate an arc between the graphite electrode and the loaded scrap steel. The heat source of the arc dissolves the scrap steel, oxidizes and removes impurities in molten steel, adjusts the composition, and then produces steel. Graphite electrodes are essential in the process of steelmaking.
Graphite electrodes consumption
Furnace structure, operation, AC/DC mode, and graphite electrode quality will directly affect electrode consumption. Generally, in production, the electrode consumption per ton of steel is 1-4kg.
We found that the consumption of graphite electrodes for steelmaking usually includes end consumption, side consumption, and loss. End loss is mainly due to sublimation and slag erosion caused by high-temperature arc heat at the end.
For example, in the AC ultra-high voltage operation refining process, the terminal consumption caused by high current increases, accounting for 50% of the total consumption. In the recently applied large-scale DC electric furnace, while using high current, the diameter of the electrode also increases accordingly, so the end loss caused by thermal shock becomes the primary consumption.
Graphite electrode vice consumption
Side consumption, and oxidation consumption, account for 50% of the total consumption of AC electric furnaces. Unlike terminal consumption, terminal consumption also occurs during power outages.
This consumption depends on electrode surface temperature, furnace surface area, gas composition and flow, and steel-making time. Generally, the bulk density of electrodes is increased to densify them to reduce oxidation consumption.
Graphite electrode for steelmaking damage consumption
Damage consumption is an abnormal consumption different from the previous two consumptions and belongs to electrode accidents. Disconnection accidents include disconnection at the electrode hole, connector disconnection, and body disconnection. Coupled with loose tripping, the blocking material loss caused by the crack expansion at the end generally accounts for 0-10%.
After the graphite electrode for steel making is energized, it will vibrate violently due to electromagnetic force and other reasons. At this time, if an external pressure exceeding the strength of the electrode is applied to generate thermal stress, the connection wire under the electrode’s main handle will break, significantly reducing production efficiency and increasing electrode consumption. You should avoid it as much as possible.