Brief Description
High-power graphite electrodes (HP)are used mainly in electric arc furnace steel production. They are presently the only products available that have the high levels of electrical conductivity and the capability of sustaining the extremely high levels of heat generated in this demanding environment. Graphite electrodes are also used to refine steel in ladle furnaces and in other smelting processes.
The High-power graphite electrodes (HP) carry the electricity that heats electric arc furnaces, the vast majority steel furnaces. They are made from petroleum coke after it is mixed with petroleum pitch, extruded and shaped, then baked to sinter it, and then graphitized by heating it above the temperature (3000 °C) that converts carbon to graphite. They can vary in size up to 11 ft. long and 30 in. in diameter.
Technical Characteristics
| Name | Unit | diameter of electrode 300mm-600mm | |||
| standard | Actual measurement | ||||
| Electrode | Nipple | Electrode | Nipple | ||
| Specific electrical resistivity | μOhm • m | 7.0-7.5 | 6.5. | 6.5-7.0 | 6th |
| Limit of mechanical resistance to bending | MPa | 9.8-10.5 | 14 | 12-15 | 15-18 |
| Elastic modulus | GPa | 12 | 16 | 12 | 14 |
| Ash content, not more than | % | 0.3 | 0.3 | 0.3 | 0.3 |
| Bulk density, not less than | g / cm3 | 1.6 | 1.7. | 1.68-1.73 | 1.75 |
| Thermal coefficient of linear expansion | × 10-6 / ℃ | 2.4 | 2.2 | 2.2 | 2 |
The Length & Diameter & Permissible Deviation
| Diameter | Length | ||||||
| Nominal diameter | Actual diameter | Nominal length | tolerance | ||||
| Millimeters (mm) | Inch (inch) | Max. (Max.) | Min (min) | mm | Length | the maximum | |
| 300 | 12 | 307 | 302 | 1600 1800 | ± 100 | -100 | -275 |
| 350 | 14 | 357 | 352 | ||||
| 400 | 16 | 409 | 403 | ||||
| 450 | 18 | 460 | 454 | ||||
| 500 | 20 | 511 | 505 | 1600/1800/2000/2200 1800/2000/2200 1800/2000/2200/2400 1800/2000/2200 1800/2000/2200 |
± 100 | -100 | -275 |
Current Capacity
| Nominal diameter | Permissible current power | The current density (A / cm2) | |
| Millimeter (mm) | Inch (inch) | ||
| 300 | 12 | 10000-13000 | 17-24 |
| 350 | 14 | 13500-18000 | 17-24 |
| 400 | 16 | 18000-23500 | 16-24 |
| 450 | 18 | 22000-27000 | 16-24 |
| 500 | 20 | 25000-32000 | 15-24 |
| 600 | 24 | 30000-36000 | 14-24 |