The diameter of super high power graphite electrode has considerable influence on the proportion of various parts. According to the International Standard of electrodes, the diameter of normal power graphite electrodes should not exceed 300mm, 350mm and 400mm for fine power graphite electrodes, medium power graphite electrodes, and high power graphite electrodes respectively. However, for super high power graphite electrodes, the diameter should not exceed 500mm, 550mm and 600mm for fine power, medium power and high power respectively. The influence of the diameter on current density of graphite electrodes is significant, which determines the service life of the electrodes.
The graphite electrode quality is decided by raw material graphite, electrode manufacturing process and electrode using degree, etc. According to quality requirements of electrodes, the roughness of the channels should be controlled within 3.2mm, and the total wall thickness should be controlled within 4%. Therefore, the allowable deviation range of the diameter of super high power graphite electrodes is within +/- 2mm, with the maximum allowable range of -2mm to +2mm.
For super high power graphite electrodes, the deviation of diameter should be strictly controlled in production, because a slight change in diameter will cause a large change on current density and service life of electrode. In order to ensure the quality of electrodes and make the production process more reliable and controllable, only batch with same diameter will be put in production, and their deviation will be maintained within -2mm to +2mm. In addition, strict process standards must be followed during the whole production process of graphite electrodes. For example, in order to ensure the stable and reliable quality of graphite electrodes, the silicon content should not exceed 0.01%, the graphitization degree of the electrodes should reach above 95% and the density should be greater than 1.61g/cm3.
In summary, super high power graphite electrodes are required to have a precise diameter, with allowable deviation range of -2mm to +2mm. The quality of electrodes should be strictly controlled to ensure that their performance can meet the requirements. In addition, strict production process standards should also be followed in order to produce quality super high power graphite electrodes.
