rp graphite electrodes
Analysis of the new standard of ultra-high power rp graphite electrodes
Determination of main technical indicators
1. Standard range With the advancement of carbon technology, the raw materials for the production of ultra-high-power rp graphite electrodess have undergone great changes. Therefore, “this standard applies to major raw materials such as high-quality needle coke” is revised to “this standard applies to major raw materials such as needle coke and coal pitch”.
(1) Since most of the rp graphite electrodes manufacturers did not carry out the elastic modulus test of the overall rp graphite electrodes, nor did they measure the speed of sound on site, the reference standard GB/T 24210 “Sound velocity method for the elastic modulus test of the overall rp graphite electrodes” was deleted. (2) The reference standard is revised to the latest test item standard.
2.1. Shape, size and allowable deviation
(1) Modify the length in Table 1 to the nominal length.
(2) Due to the increasing capacity of electric furnaces used by users, according to the corporate standards of IEC and SGL companies, this standard adds relevant requirements for the dimensions of Φ750mm and Φ800mm rp graphite electrodes and joints.
(3) In order to meet the international standard IEC6023-2005 and improve the versatility of the product, the maximum actual diameter of the rp graphite electrodes with a nominal diameter of 350 mm was changed from 357 mm to 358 mm, and the nominal diameter of the rp graphite electrodes with a nominal diameter of 700 mm was changed to 358 mm. The minimum actual diameter is changed from 708 mm to 710 mm, and the minimum actual diameter of the black part is changed from 705mm to 707mm.
(4) Due to the Φ550mmrp graphite electrodes market’s demand for the length of 2700 mmrp graphite electrodes, the nominal length of 2700 mm has been increased; the nominal length of rp graphite electrodes of Φ650 mm and above has been increased by two standard nominal lengths of 2000 mm and 2200 mm; for those of Φ600 mm and above The rp graphite electrodes has a nominal length of 3000 mm.
(5) For the convenience of users, the maximum standard length deviation with a nominal length of 2700 mm has been increased from the original standard of 150 mm to +200 mm; the allowable deviation of the standard nominal length of 3000 mm is determined to be the same as the nominal length of 2700 mm. The length is the same.
(6) For the convenience of users, the allowable short-length rp graphite electrodes in each batch in the supply shall not exceed 15%, which is modified to 5%. See Article 3.3 of this standard.
(7) In order to improve the connection quality and product performance of the rp graphite electrodes, the gap between the connecting end faces of the two rp graphite electrodess is not more than 0.4mm, and is corrected to 0.05mm. See Article 3.5 of this standard.
(8) 3.6 “If there are special requirements for the rp graphite electrodes specification, it shall be negotiated and determined by the supplier and the buyer.”
2.2. Physical and chemical indicators
(1) Due to the continuous improvement of user requirements, the quality of ultra-high power rp graphite electrodes products is also continuously improving. In order to improve the performance of the product, improve the quality of the product, and better meet the requirements of users, some indicators of the Φ300~500mm ultra-high power rp graphite electrodes have been revised. Φ300~400mm: The bulk density of rp graphite electrodes is revised from 1.65g/cm3 to 1.67g/cm3; the joint is revised from 1.72g/cm3 to 1.74g/cm3. Φ450~500m M: The bulk density of the rp graphite electrodes is corrected from 1.64g/cm3 to 1.66g/cm3; the bending strength of the rp graphite electrodes is corrected from 10.0MPa to 10.5mpa; the resistivity of the rp graphite electrodes is corrected from 6.5μΩ·M to 6.3μΩ·M; the bulk density of the joint Corrected from 1.70g/cm3 to 1.75g/cm3; revised joint bending strength from 16.0MPa to 20.0MPa. The resistivity of joints of Φ500m and below is revised from 5.5μΩ·m to 5.3μΩ·m. Due to the use of additives, the ash content was changed from 0.3% to 0.5%.
(2) As the market share of large ultra-high power rp graphite electrodess continues to increase, in order to promote the development of production enterprises, the index requirements for large ultra-high power rp graphite electrodess of Φ550~800mm have also been improved. The revised technical indicators are shown in Table 1 (standards are shown in Table 4).
3. Concluding remarks
(1) The revised standard improves the joint’s flexural strength, bulk density and other indexes, determines the indexes of large-scale ultra-high power rp graphite electrodes, and proposes the size and tolerance requirements of Φmmrp graphite electrodes, which is for the production and users of carbon companies. Use to provide technical support and quality assurance, promote the improvement and development of the quality of ultra-high power rp graphite electrodes products, increase the market share of domestic production products, and improve the economic benefits of enterprises.
(2) According to the actual situation of production and user use, the IEC international standard is equivalent to the size and tolerance requirements, and some tolerance requirements are higher than the IEC standard, so the standard is more scientific and reasonable.