lf eaf graphite electrode factory

Pubdate: 08-05 2021

EDM characteristics of lf eaf graphite electrode material

lf eaf graphite electrode factorylf eaf graphite electrode factory

EDM characteristics of graphite materials

(1) EDM speed Graphite is a non-metallic material with a very high melting point of 3650 ℃, while the melting point of copper is 1083 ℃, so the lf eaf graphite electrode can withstand higher current setting conditions. When the discharge area and the size of the lf eaf graphite electrode are scaled larger, the superiority of the graphite material’s high-efficiency rough machining is more obvious. The thermal conductivity of graphite is 1/3 of copper, and the heat generated during the discharge process can be used to remove metal materials more effectively. Therefore, its processing efficiency is also higher than that of copper lf eaf graphite electrode in medium and fine processing. According to machining experience, under the correct conditions of use, the electrical discharge machining speed of the lf eaf graphite electrode is 1.5 to 2 times faster than that of the copper lf eaf graphite electrode as a whole.

(2) Loss of lf eaf graphite electrode lf eaf graphite electrode has the characteristics of being able to withstand high current conditions. In addition, under appropriate roughing conditions, the erosion and working fluid generated during processing of carbon-containing steel workpieces The carbon particles in the decomposition product produced at high temperature will adhere to the surface of the lf eaf graphite electrode to form a protective layer under the effect of the polarity effect, ensuring that the lf eaf graphite electrode is thick The loss in processing is extremely small, even “zero loss”. The main loss of lf eaf graphite electrode in EDM comes from rough machining. Although the loss rate of finishing setting conditions is relatively high, because the reserved machining allowance of parts is not much, the amount of machining erosion is small, and the overall loss is Also less. In general, the loss of the lf eaf graphite electrode in the rough machining of high current is less than that of the copper lf eaf graphite electrode, and the loss in the finishing process may be slightly greater than that of the copper lf eaf graphite electrode. The loss of the lf eaf graphite electrode of the two is equivalent. .

(3) Surface quality The particle diameter of graphite material directly affects the surface roughness of EDM, the smaller the diameter, the lower the surface roughness value can be obtained. A few years ago, graphite materials with a particle diameter of φ5 μm were used, and the best surface for EDM can only reach VDI18 (Ra0.8 μm). Nowadays, the particle diameter of graphite materials can reach within φ3 μm, which is the best surface for EDM. It can stably reach VDI12 (Ra0.4 μm) or a finer level, but the lf eaf graphite electrode cannot be used for mirror EDM. The resistivity of copper material is low, and the structure is dense. EDM is easy to obtain a stable processing state, and it can be processed stably under difficult conditions. The surface roughness can be less than Ra0.1 μm, and it can be mirrored EDM. . It can be seen that if the electrical discharge machining pursues an extremely fine surface, it is more appropriate to use copper materials to make the lf eaf graphite electrode. This is the main advantage of the copper lf eaf graphite electrode over the lf eaf graphite electrode. However, under the condition of high current setting, the surface of the copper lf eaf graphite electrode is prone to become rough and even cracks, while the graphite material does not have this problem. The surface roughness requirement is VDI26 (Ra2.0 μm) For cavity processing, one lf eaf graphite electrode can be used to complete the machining process from coarse to fine, achieving a uniform texture effect and no defects on the surface. In addition, due to the difference in the structure of graphite and copper, the corrosion points of the surface discharge of the lf eaf graphite electrode are more regular than that of the copper lf eaf graphite electrode. Therefore, when processing the same surface roughness of VDI20 and above, use the lf eaf graphite electrode to process the workpiece The surface granularity is more distinct, and the texture effect is better than the discharge surface effect of the copper lf eaf graphite electrode.

(4) Machining accuracy The thermal expansion coefficient of graphite material is small, and the thermal expansion coefficient of copper material is 4 times that of graphite material. Therefore, lf eaf graphite electrode is less prone to deformation than copper lf eaf graphite electrode in electrical discharge machining, and it can obtain more stable and reliable Precision. Especially when processing deep and narrow ribs, local high temperature is likely to cause bending and deformation of the copper lf eaf graphite electrode, while the lf eaf graphite electrode does not; for the copper lf eaf graphite electrode with a large depth-to-diameter ratio, when processing settings It is also necessary to compensate a certain thermal expansion value to correct the size, but the lf eaf graphite electrode does not need it.

(5) Weight of lf eaf graphite electrode Graphite material is less dense than copper, and the weight of the same volume of lf eaf graphite electrode is only 1/5 of that of copper lf eaf graphite electrode. It can be seen that the larger lf eaf graphite electrode uses graphite material, which greatly reduces the load on the spindle of the EDM machine tool. The lf eaf graphite electrode will not cause problems such as inconvenience in clamping and yaw displacement during processing due to its heavy weight. It can be seen that it is very meaningful to use lf eaf graphite electrode in the processing of large molds.

(6) Difficulty in making lf eaf graphite electrode The machining performance of graphite material is good, and the cutting resistance is only 1/4 of that of copper. Under the correct processing conditions, the efficiency of milling lf eaf graphite electrode is 2 of that of copper lf eaf graphite electrode. ~3 times. The lf eaf graphite electrode is easy to clean the corners, and the workpiece that is usually completed by multiple lf eaf graphite electrodes can be designed into a whole lf eaf graphite electrode for processing. The unique particle structure of the graphite material makes the lf eaf graphite electrode milled and formed without burrs. For complex shapes that are not convenient to remove the burrs, it directly meets the requirements of use, eliminating the need for manual polishing of the lf eaf graphite electrode. The shape changes and dimensional errors caused by polishing are eliminated. It should be noted that because graphite is a dust accumulation, a large amount of dust will be generated when milling graphite, so the milling machine must have a sealing and dust suction device. If you need to use EDM wire cutting to process lf eaf graphite electrode, its processing performance is not as good as that of copper materials, and the cutting speed is about 40% slower than that of copper.

(7) The installation of lf eaf graphite electrode and the use of graphite materials have good adhesion. Conductive glue can be used to bond graphite to the fixture for milling lf eaf graphite electrode and electric discharge machining, which can be omitted on the lf eaf graphite electrode material. The process of machining screw holes saves working time. Graphite materials are relatively brittle, especially the small and narrow lf eaf graphite electrode, which is easy to break when subjected to external force during use, but it can be immediately known that the lf eaf graphite electrode is damaged. If it is a copper lf eaf graphite electrode, it will only bend and not break. This situation is very dangerous and difficult to find during use, and it is easy to cause the workpiece to be scrapped.

(8) Prices In recent years, the price of copper materials has continued to rise, and major graphite manufacturers continue to improve the process of making graphite to make it more cost-effective. Under the same volume, the price of the universal lf eaf graphite electrode material is equivalent to that of the copper lf eaf graphite electrode material, and the price of fine graphite will be higher than that of the copper lf eaf graphite electrode. In summary, among the 8 EDM characteristics of lf eaf graphite electrode, its advantages are obvious: the efficiency of milling lf eaf graphite electrode and electric discharge machining is significantly better than that of copper lf eaf graphite electrode, and the weight of large lf eaf graphite electrode is small. , Dimensional stability is good, the sheet lf eaf graphite electrode is not easy to be deformed, the surface texture is better than copper, and the price is lower. The disadvantage of graphite material is that it is not suitable for fine surface electrical discharge machining below VDI12 (Ra0.4 μm), and the efficiency of making lf eaf graphite electrode by wire EDM is low. <p>But from a practical point of view, an important reason that affects the effective promotion of graphite materials in China is that milling lf eaf graphite electrode requires a special graphite processing machine, which places new requirements on the processing equipment of mold companies. Some small businesses may not have this condition. In general, the advantages of the characteristics of the lf eaf graphite electrode cover most of the machining occasions of EDM, it is worthy of promotion and application, and the long-term benefits are considerable. The deficiencies of its fine surface processing can be compensated by using the copper lf eaf graphite electrode.

When lf eaf graphite electrode factory was founded, it established the development strategy of “science and technology, innovation, and leadership”, adhering to the business philosophy of “quality first, service first”, after process improvement, quality improvement, and market development, Hongsheng Carbon has become a The largest graphitization processing company in Hebei, Hebei and Mongolia. Its main business includes lf eaf graphite electrode, Shijiazhuang lf eaf graphite electrode, and Datong silicon carbide.


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