| HP TECHNICAL PARAMETERS | ||||||||
| (mm)Nominal Diameter | (mm)Nominal Diameter | |||||||
| Item | Unit | YB/T4090 Industry Standard) | HP (Measured Value) | |||||
| 200\400 | 450\500 | 600\700 | 600\700 | 450\500 | 450\500 | |||
| Electric Resistivity | Electrode | μQM | ≤7.0 | ≤7.5 | ≤7.5 | 5.6-6.5 | 5.8-6.7 | 5.8-6.8 |
| Nipple | ≤6.3 | ≤6.3 | ≤6.3 | 3.5-4.3 | 3.5-4.2 | 3.5-4.2 | ||
| Bulk Density | Electrode | g/cm³ | ≥1.60 | ≥1.60 | ≥1.60 | 1.7.-1.75 | 1.72-1.74 | 1.70-1.72 |
| Nipple | ≥1.72 | ≥1.72 | ≥1.72 | 1.80-1.82 | 1.82-1.84 | 1.82-1.85 | ||
| Flexural Strength | Electrode | MPa | ≥10.5 | ≥10 | ≥8.5 | 12.0-15.0 | 11.0-15.0 | 10.0-12.0 |
| Nipple | ≥17.0 | ≥17.0 | ≥17.0 | 22.0-26.0 | 22.0-26.0 | 24.0-28.0 | ||
| CTE | Electrode | 10℃ | ≤2.4 | ≤2.4 | ≤2.4 | 1.7-2.0 | 1.6-2.0 | 1.6-2.0 |
| Nipple | ≤2.2 | ≤2.2 | ≤2.2 | 1.4-1.8 | 1.4-1.8 | 1.4-1.8 | ||
| Elastic Modulus | Electrode | GPa | ≤14.0 | ≤14.0 | ≤14.0 | 9.0-12.0 | 9.0-11.5 | 9.0-11.5 |
| Nipple | ≤16.0 | ≤16.0 | ≤16.0 | 14.0-16.0 | 15.0-18.0 | 15.0-18.0 | ||
| Ash | Electrode | % | ≤0.5 | ≤0.5 | ≤0.5 | ≤0.5 | ≤0.5 | ≤0.5 |
| Nipple | ||||||||
| Nominal Diameter | Cross-Sectional Area | YT/t4090(Industry Standard) | HP(Enterprise Standard) | |||
| Permissible Current Load | Current Density | Permissible Current Load |
Current Density | |||
| in | mm | cm² | A | A/cm² | A | A/cm² |
| 14 | 350 | 937 | 17400-24000 | 17-27 | 18270-25200 | 19-26 |
| 16 | 400 | 1275 | 21000-31000 | 16-24 | 22050-32550 | 17-26 |
| 18 | 450 | 1622 | 25000-40000 | 15-24 | 26250-42000 | 16-26 |
| 20 | 500 | 2000 | 30000-48000 | 15-24 | 31500-50400 | 16-25 |
| 22 | 550 | 2427 | 34000-53000 | 14-22 | — | — |
| 24 | 600 | 2892 | 38000-58000 | 13-21 | — | — |
| 28 | 700 | 3935 | 45000-72000 | 12-19 | — | — |
|
GUIDANCE TO ANALYSIS OF ELECTRODE PROBLEMS |
|||||||
| Factors | Body Breakage | Nipple Breakage | Loosening | Tip Spalling | Bolt loss | Oxidation | Consumption |
| Nonconductor In Charge | ◆ | ◆ | |||||
| Heavy Scrap In Charge | ◆ | ◆ | |||||
| Transformer Capacity Too Large | ◆ | ◆ | ◆ | ◆ | ◆ | ◆ | |
| Phase Imbalance | ◆ | ◆ | ◆ | ◆ | ◆ | ||
| Phase Rotation | ◆ | ◆ | ◆ | ||||
| Excessive Vibration | ◆ | ||||||
| Clamper Pressure Too High Or Too Low | ◆ | ◆ | ◆ | ||||
| Roof Electrode Socket Disalignment With Electrode | ◆ | ◆ | ◆ | ||||
| Water Sprayed On Electrodes Above Roof | △ | ||||||
| Scrap Preheating | △ | ||||||
| Secondary Voltage Too High | ◆ | ◆ | ◆ | ◆ | ◆ | ||
| Secondary Current Too High | ◆ | ◆ | ◆ | ◆ | ◆ | ◆ | |
| Power Factor Too Low | ◆ | ◆ | ◆ | ||||
| Oil Consumption Too High | ◆ | ◆ | ◆ | ◆ | |||
| Oxygen Consumption Too High | ◆ | ◆ | ◆ | ◆ | |||
| Long Time Gap From Tapping To Tapping | ◆ | ◆ | |||||
| Electrode Dipping | ◆ | ◆ | |||||
| Dirty Joint | ◆ | ◆ | |||||
| Poorly Maintained Lift Plug And Tightening Tool | ◆ | ◆ | ◆ | ||||
| Insufficient Joint Tightening | ◆ | ◆ | ◆ | ||||
| Note:△Indicates Increased Performance.◆ Indicates Decreased Performance. | |||||||
The high-power graphite electrodes produced by mainly made of petroleum coke and needle coke as raw materials, coal tar pitch as binder, and are made by calcination, batching, mixing, pressing, calcination, graphitization, and machining. They are conductors that release electricity in the form of an arc in an electric arc furnace to heat and melt the furnace material. According to their quality indicators, they can be divided into ordinary power graphite electrodes, high-power graphite electrodes, and ultra-high power graphite electrodes. Graphite electrodes are commonly used in electric arc furnaces (for steelmaking) and submerged arc furnaces (for producing ferroalloys, pure silicon, phosphorus, calcium carbide, etc.). And resistance furnaces, such as graphitization furnaces for producing graphite electrodes, glass melting furnaces, and electric furnaces for producing diamond sand. Can be processed according to customer requirements, mainly used for arc furnace steelmaking.
Product Advantage
(1) The increasing complexity of mold geometry and the diversification of product applications have led to higher requirements for the discharge accuracy of spark machines. The advantages of graphite electrodes are easy processing, high discharge machining removal rate, and low graphite loss. Therefore, some group based spark machine customers have abandoned copper electrodes and switched to graphite electrodes. In addition, some special shaped electrodes cannot be made of copper, but graphite is easier to form and copper electrodes are heavier, making them unsuitable for processing large electrodes. These factors have led to some group based spark machine customers using graphite electrodes.
(2) Graphite electrodes are easier to process and have a significantly faster processing speed than copper electrodes. For example, using milling technology to process graphite, its processing speed is 2-3 times faster than other metal processing and does not require additional manual processing, while copper electrodes require manual grinding. Similarly, if high-speed graphite machining centers are used to manufacture electrodes, the speed will be faster, the efficiency will be higher, and there will be no dust problem. In these machining processes, selecting tools with appropriate hardness and graphite can reduce tool wear and copper electrode damage. If comparing the milling time of graphite electrodes and copper electrodes, graphite electrodes are 67% faster than copper electrodes. In general, in discharge machining, using graphite electrodes is 58% faster than using copper electrodes. In this way, the processing time is significantly reduced, while also reducing manufacturing costs.
(3) The design of graphite electrodes is different from that of traditional copper electrodes. Many mold factories usually have different reserve amounts for rough and precision machining of copper electrodes, while graphite electrodes use almost the same reserve amount, which reduces the frequency of CAD/CAM and machine processing. This alone is enough to greatly improve the accuracy of the mold cavity.
Processing Forms of Graphite Materials
There are three main forms of processing graphite electrodes: pressurized vibration method, CNC automatic forming method, and mechanical processing method.
Graphite materials can be processed using methods such as turning, milling, drilling, and grinding. In addition, graphite materials are prone to fly ash during mechanical processing, which has adverse effects on processing equipment and operators.
Processing Forms of Graphite Materials
(1) Long production cycle. The production cycle of ordinary power graphite electrodes is about 45 days, and the production cycle of ultra-high power graphite electrodes is more than 70 days. However, the production cycle of graphite electrode joints that require multiple impregnations is longer.
(2) High energy consumption. Producing 1 ton of ordinary power graphite electrodes requires approximately 6000 kW · h of electrical energy, thousands of cubic meters of gas or natural gas, and approximately 1 ton of metallurgical coke particles and powder.
(3) There are multiple production processes. The production process includes raw material calcination, crushing and grinding, batching, kneading, shaping, roasting, impregnation, graphitization, and mechanical processing. Its production requires many specialized mechanical equipment and kilns with special structures, and the construction investment is large, with a long investment payback period.
(4) A certain amount of dust and harmful gases are generated during the production process, and it is necessary to take comprehensive ventilation and dust reduction measures as well as environmental protection measures to eliminate harmful gases.
(5) The required carbonaceous raw materials for production, such as petroleum coke and coal tar pitch, are by-products of refining and coal chemical enterprises. The quality and stability of the raw materials are difficult to fully guarantee, especially needle coke, modified electrode pitch, and special impregnating agent pitch with low quinoline insoluble content used in high-power and ultra-high power graphite electrode production. It is urgent for China's petroleum and coal chemical processing enterprises to attach importance to and actively cooperate.
Production Application
(1) Used for electric arc steelmaking furnaces
(2) Used for mining electric furnaces
(3) Used for resistance furnaces
(4) Used for preparing irregular graphite products
Company Introduction
Handan Tuoda New Material Technology Co., Ltd. is a professional graphite supplier dedicated to the research and development, processing, manufacturing, and sales of graphite products. The company has strong economic strength and advanced technical support, and has developed graphite products with domestic cash technology level, providing customers with integrated services from material selection to design and processing. The product is widely used in various fields, including the electronic semiconductor industry, mechanical processing industry, aerospace industry, and automotive industry. We provide customers with high-quality products and sincere services, continuously learn and explore technology, and have established cooperative relationships with manyenterprises.
