450mm graphite electrode manufacturers
450mm graphite electrode manufacturers processing step
Graphitization refers to the process of high temperature heat treatment in which the carbon product is heated to above 2300 ℃ in the maintenance medium in the high temperature electric furnace to transform the amorphous chaotic layer structure carbon into a three-dimensional ordered graphite crystalline structure.
The intention and effect of graphitization:
①Improve the electrical conductivity and thermal conductivity of carbon materials (resistivity is reduced by 4-5 times, and thermal conductivity is improved by about 10 times);
②Improve the thermal vibration resistance and chemical stability of carbon materials (the linear expansion coefficient is reduced by 50-80%);
③Make the carbon material have lubricity and anti-wear properties;
④Remove impurities and improve the purity of carbon materials (the ash content of the product is reduced from 0.5-0.8% to about 0.3%).
Completion of the graphitization process:
The graphitization of carbon materials is carried out at a high temperature of 2300-3000 ℃, so the industry can only be completed by electric heating, that is, the electric current directly passes through the heated roasted product. At this time, the roasted product loaded into the furnace has passed the current to generate high temperature. The conductor is again the target of being heated to a high temperature.
At present, the widely used furnace types are Acheson () graphitization furnace and internal heat series (LWG) furnace. The former has large output, large temperature difference, and high power consumption, while the latter has short heating time, low power consumption, uniform resistivity, but is not well installed.
The control of the graphitization process is controlled by an electric power curve that is compatible with the heating situation after temperature measurement. The Acheson furnace is 50-80 hours when the power is turned on, and the LWG furnace is 9-15 hours.
Graphitization consumes a lot of electricity, generally 3200-, and the process cost accounts for about 20-35% of the entire production cost
Viewing of graphitized products: appearance knocking, resistivity test
Machining: The purpose of machining carbon graphite materials is to rely on cutting to achieve the required size, shape, precision, etc., to make the electrode body and joints that meet the application requirements.
The 450mm graphite electrode processing is divided into two independent processing processes, the electrode body and the joint.
The body processing includes three processes: boring and rough flat end face, turning outer circle and fine flat end face, and thread milling. The processing of conical joints can be divided into 6 processes: cutting, flat end face, turning taper surface, milling thread, and drilling bolt. And slotting.
Electrode connector connection method: conical connector connection (one inch three buckles and one inch four buckles), cylindrical connector connection, concave-convex connection (male and female buckle connection)
450mm graphite electrode processing precision control: thread taper deviation, thread pitch, joint (hole) large diameter deviation, joint hole coaxiality, joint hole perpendicularity, electrode end surface flatness, joint four-point deviation, etc. Use special ring gauges and board gauges to check.
View the finished electrode: accuracy, weight, length, diameter, volume density, resistivity, pre-installed cooperation accuracy, etc.