Industry News

Home > News > Industry News > Views

Home > News > Industry News > Views

The Consumption Mechanism of Graphite Electrode in Electric Arc Furnace

Time:2020-10-21 Views:
The graphite electrode is the last part of the electric arc furnace power supply network. The end of the graphite electrode produces strong electric arc melt furnace burden to heat the molten steel. That is, the electrode is the central hub that converts electric energy into heat. The electrode is subjected to high temperature when working, and the furnace gas is oxidized. As well as the effects of collapse and impact, especially when the two electrodes are connected, the resistance is higher than other places, the conductivity is lower, and it is easy to trip, oxidize, fall off, and break, which causes great electrode consumption and prolongs the smelting time and reduces productivity.

Regarding the consumption of graphite electrodes, it can be divided into the consumption of the graphite electrode end and outer surface in the electric furnace, the consumption of the graphite electrode residue generated in the smelting, and the electrode surface oxidation and peeling accompanied by cracking, and the consumption of falling pieces, the direct loss caused by the broken graphite electrode in smelting. Regardless of the consumption of any part of the graphite electrode, it can be divided into two categories, namely, logistics consumption and chemical consumption. Physical consumption includes electrode loss caused by mechanical and electromagnetic forces such as electrode breakage and shedding, while chemical consumption mainly includes electrode consumption caused by high temperature oxidation of the electrode and corrosion by slag.


In the steelmaking process of graphite electrodes, due to the high temperature environment, the surface of the electrode reacts with oxygen to produce carbon and oxygen. Graphite electrodes are stable at low temperatures and easily oxidized at high temperatures. Generally, carbon products begin to oxidize at about 450℃ in the air. Graphite products with a high degree of graphitization begin to oxidize at about 600℃, and the oxidation increases sharply after 750℃ and it increases with the increase in temperature, and is oxidized when heated to 900℃ in water vapor. That is, the main factors that affect the side oxidation of the graphite electrode are high temperature and oxidizing atmosphere, which is the electrode oxidation consumption, especially with the successive application of new technologies such as furnace door oxygen lance, oil oxygen boosting, EBT cluster oxygen lance and furnace wall oxygen lance. The intensity of oxygen supply in the furnace is increased, and the oxidizing atmosphere is strengthened, which further increases the electrode consumption. In addition, since the electrode ends are in direct contact with the arc, the end electrodes are sublimated and consumed. The electrode part is in contact with the molten pool, and the carbon element is absorbed by the molten pool as erosion consumption. The electrode is subjected to electromagnetic force, mechanical force and impact force of solid raw materials during operation, causing fracture and avalanche consumption.


If you has any inquiry about graphite electrodes, please feel free to contact our factory.