graphite electrode microstructure

graphite electrode microstructure

How is graphite electrode consumed in electric furnace steelmaking?

How is graphite electrode consumed in electric furnace steelmaking? The consumption of graphite electrode is mainly related to the quality of the electrode itself, but also to the steelmaking operation and process (such as the current density through the electrode, the type of steel smelted, the quality and lumpiness of scrap steel, the duration of oxygen blowing, etc.).

(1) The electrode end is consumed. Its consumption includes the sublimation of graphite material caused by the high temperature of the arc and the loss of the chemical reaction between the electrode end and the molten steel and slag. The consumption of the electrode end is also related to whether the electrode is inserted into the molten steel to increase carbon.

(2) Oxidation loss on the outer surface of the electrode. In recent years, in order to increase the smelting rate of the electric furnace, the oxygen blowing operation has been adopted, which leads to an increase in the oxidation loss of the electrode. In general, the oxidation loss on the outer surface of the electrode accounts for about 50% of the total electrode consumption.

(3) Loss of residual body of electrode or joint. The electrode is used continuously to a small section of electrode or joint (ie, residual body) where the upper and lower electrodes are connected, which is easy to fall and increase consumption.

(4) The electrode is broken, the surface is peeled off, and the loss of the block. These three types of electrode losses are collectively referred to as mechanical losses. The reason for electrode breakage and shedding is the dispute between the steelmaking plant and the graphite electrode manufacturer to determine the quality accident, because it may be due to the quality and processing of the graphite electrode (especially the electrode joint). The problem may also be a problem in steelmaking operations. Electric furnace steelmaking plants generally refer to the inevitable electrode consumption such as oxidation and sublimation at high temperature as &;net consumption&;, &;net consumption&; plus mechanical losses and residual losses such as breaking are called &;gross consumption& ;. At present, the unit consumption of graphite electrode per ton of electric furnace steel in China is 1.5~6kg. In the process of steel smelting, the electrode is gradually oxidized and consumed into a cone. During the steelmaking process, the taper of the electrode and the redness of the electrode body are often observed as an intuitive method to measure the oxidation resistance of the graphite electrode.