graphite electrode HP450mm

How to correctly select electrodes when making steel in an electric arc furnace?

 

According to the design characteristics of the electric arc furnace, electrodes that are suitable for the production of the electric arc furnace should be reasonably selected, and products with the best cost performance should be chosen. It is very necessary to carefully select electrodes suitable for each furnace. The special performance of the steelmaking furnace, the feeding method, the maximum current intensity, the length of the electrode column under the clamps, the distance between the furnace side wall and the electrode circumference, etc. are all factors that must be considered when choosing and using electrodes for electric arc furnaces.

 

2. What influence does the resistivity performance have on the use of electrodes during steelmaking?

 

The resistivity of graphite electrodes is a physical indicator reflecting the electrical conductivity of the electrodes, which is related to the manufacturing process of the electrodes. The state has qualitative specified values for the resistivity of graphite electrodes of different specifications and varieties. Generally speaking, when steel mills select electrodes of a certain specification, they must choose within the resistivity range stipulated by the national metallurgical standards. Excessively high resistivity will cause the electrodes to turn red and heat up when powered on. Increase the oxidation consumption of the electrode.

 

3. What influence does volumetric density performance have on the use of electrodes during steelmaking?

 

The volumetric density of graphite electrodes reflects the compactness of the electrodes and is closely related to the manufacturing process of the electrodes. The state has stipulated values for the volume density of graphite electrodes of different specifications and varieties. Products with a low bulk density indicate that the overall structure of the product has a higher porosity. At high temperatures, the oxidation rate of the product is faster, which can easily lead to increased electrode consumption. Generally speaking, when steel mills select electrodes, it is better if the bulk density of the electrode is within the specified value. However, a higher bulk density is not necessarily better, because some electrodes with excessively high bulk density sometimes have poor thermal shock resistance. Surface spalling, chipping and cracking are prone to occur during steelmaking, which will instead affect steelmaking.

 

4. Why should steel mills prevent the mixed use of products from multiple manufacturers when using graphite electrodes?

 

The graphite electrodes used in steel mills are often supplied by multiple manufacturing enterprises. During steelmaking, the products of these enterprises are mixed and used. This not only makes it difficult for steel mills to statistically analyze the consumption of individual products, but also, due to the different raw materials and manufacturing processes adopted by each manufacturer, there are certain differences in the physical and chemical properties and processing tolerances of electrodes and joints from different manufacturers. Therefore, when used interchangeably, the resulting fit tolerances and other issues can easily lead to electrode detachment and breakage. The correct way to use it is to use a product from one manufacturer alone and then connect it to another manufacturer's product after use. It is necessary to reduce the frequency of replacing electrodes from different manufacturers. Electrodes from the same manufacturer should use the corresponding connectors from the same manufacturer to prevent interchangeability.

 

5. What are the characteristics of needle coke?

 

Needle coke is a high-quality carbon raw material, which is divided into coal-based and oil-based types. Its surface shows obvious strip-like patterns. When broken, most of them are long strip-like needle-like fragments. Under a microscope, fibrous structures can be observed, thus it is called needle coke. Needle coke is prone to graphitization at temperatures above 2000 degrees. The graphite electrodes made from it not only have a low resistivity and a high bulk density, but also a small coefficient of thermal expansion. They are essential raw materials for the production of ultra-high power electrodes and high power electrodes. The price of needle coke is much higher than that of ordinary coke. Currently, it is about 5 to 8 times higher.

 

6.Different power electric furnaces should use graphite electrodes of different powers. graphite electrodes are classified by grade into (regular power)RP graphite electrode,( 68336884,high power)HP graphite electrode, and (ultra high power)UHP graphite electrode.