Author: graphelectrode.com

DC electric arc furnace is a new type of electric furnace steelmaking equipment developed in the early 1980s. The initial DC electric arc furnace was transformed from the original AC electric arc furnace. How to Choose Graphite Electrode for DC Electric Arc Furnace? Some used 3 graphite electrodes and some used 2 graphite electrodes.

After the mid-1980s, most of the newly designed DC electric arc furnaces only used one graphite electrode. Compared with AC electric arc furnaces with three graphite electrodes of the same power, the total surface area of the electrode that was oxidized at a high temperature was greatly reduced. The DC arc furnace operating at the same high power can reduce the (hp) graphite electrode consumption per ton of steel by about 50%. DC arc furnace current does not produce skin effect and proximity effect when passing through the electrode. The current distribution is uniform on the electrode cross section, and the stability of the DC arc is good. The mechanical vibration is small during operation, and the noise of the electric furnace is also low.

The diameter of the graphite electrode used in the DC electric arc furnace is also calculated based on the capacity of the electric furnace and the allowable current density of the electrode. For ultra-high-power electric furnaces with the same input power, a DC furnace using one graphite electrode has a larger electrode diameter. For example, an AC arc furnace with a capacity of 150t uses an electrode with a diameter of 600mm, while a DC arc furnace with the same capacity uses an electrode with a diameter of 700 ~ 750mm. DC arc furnaces have higher quality requirements for graphite electrodes than graphite electrodes used in AC arc furnaces.

Based on the different standards of various graphite electrode manufacturers, the grades of graphite electrodes are generally as follows:

• Regular graphite electrode (RP)
• Impregnated graphite electrode
• High Power Graphite Electrode (HP)
• SHP Graphite Electrode (SHP)
• Ultra High Power Graphite Electrode (UHP)

The graphite electrodes of Rongsheng graphite electrode manufacturer are equipped with tapered joints, which comply with national standards and international standards such as NEMA CG1, IEC 60239, JIS R7201 and so on.

The use and performance of graphite electrodes:

1. Used in steelmaking electric arc furnace, refining furnace, as conductive electrode;
2. Used in industrial silicon furnace, yellow phosphorus furnace, corundum furnace, etc., as conductive electrode.

Performance of Graphite Electrode:

• Good conductivity
• Strong thermal shock resistance
• High mechanical strength

Applications of graphite electrodes

In actual use, the specifications and grades of graphite electrodes should be selected according to the specific furnace conditions. The first factor is the maximum current intensity. At the same time, the influence of other factors, such as the characteristics of the electric furnace, the type of charge, the smelting time, the amount of oxygen blowing, the mechanical requirements, and the steelmaking process system, must also be considered.

Generally, the physical and chemical indicators of most grade graphite electrodes have been standardized. However, in the process of use, the influence of temperature on some indicators must be considered sometimes.

Precautions when using graphite electrodes:

● According to the capacity of the electric furnace and the load of the transformer, select the grade and diameter of the electrode appropriately.
● When charging the electric furnace, a large piece of charge should be installed on the bottom of the furnace to prevent the charge from falling and hitting the electrode. During the smelting process, a large amount of non-conductive objects, such as lime, should be prevented from accumulating directly under the electrode, otherwise it will affect the electrode current, and even cause the electrode to break.
● Pay attention to the position of the furnace cover. If the furnace cover is misaligned, the furnace cover will be scratched when the electrode is raised and lowered, resulting in electrode damage.
● When connecting the electrodes, if there is any defect in the connector plugs, replace them and then connect them.
● After the electrode is connected, if there is a gap on the connection surface, be sure to find out the cause. Use after the gap is eliminated.
● The electrode must be used vertically.
● The electrode holder should be clamped between the upper and lower cords of the top electrode. It is strictly forbidden to sandwich the electrode in the cord (joint hole) and the middle electrode, otherwise the electrode column may be easily broken.
● Because the raw materials and production processes of different manufacturers may be different, the physical and chemical properties of the electrodes are also different. It is recommended that the connectors and electrodes produced by different manufacturers not be used in series.

RS High Quality Graphite Electrode Manufacturer. Graphite electrodes is specifically made from petroleum coke and needle coke as raw materials, and coal tar pitch as a binder, which is prepared through calcining, compounding, kneading, pressing, calcining, graphitizing and machining and is launched in an electric arc furnace electrical energy on the charge heating and melting of the conductor.

Ultra High Power Graphite Electrode

Ultra-high-power graphite electrode can allow current densities greater than 25 A / cm2 and are mainly used in ultra-high-power steelmaking electric arc furnaces.

UHP Graphite Electrode Advantages

UHP Graphite electrode has good electrical properties and chemical stability, high mechanical strength at high temperatures, less impurities, good vibration resistance. It is a good conductor of heat and electricity.

• Processing speed is faster. Under normal circumstances, graphite machining speed can be 2 to 5 times faster than copper; and discharge processing speed is 2 to 3 times faster than copper;
• The material is more difficult to deform. Obvious advantages in the thin-walled electrode processing.
• Lighter weight. The density of graphite is only 1/5 of copper, large electrode for electrical discharge machining, can successfully lessen the gadget tool (EDM) burden; more suitable for large mould applications.

RS Graphite Electrode Manufacturer

According to the usage of distinct strength and current, the usage of exceptional refractory raw materials and manufacturing technology, may be divided into rp graphite electrodes, hp graphite electrodes, uhp graphite electrodes. Graphite electrode has proper electrical properties and chemical stability, excessive mechanical energy at excessive temperature, low impurity content, top vibration resistance, is a superb conductor of heat and electricity.

Graphite Electrode Application, in electric arc furnaces steel production, graphite electrodes are commonly used. They are currently the best products be used, and that have the high levels of electrical conductivity and the capability of maintaining the extremely excessive levels of heat generated in this working environment. Graphite electrodes are also used to refine metallic in ladle furnaces and in other smelting processes.

According to the difference in power of the electricity served, RS graphite electrodes manufacturer uses different refractory raw materials and production technology, producing the graphite electrodes can be divided into ordinary power graphite electrodes, high power graphite electrode, ultra-high power graphite electrodes.

RS Graphite electrode has good electrical properties and chemical stability. In details, all kinds of the graphite electrode has advantages of high mechanical strength, low impurity content and good vibration resistance. Graphite electrodes are good conductors of heat and electricity.

In the graphite electrode application side, graphite electrode is widely used in:

• steelmaking electric furnace,
• refining furnaces,
• submerged arc furnaces,
• and other smelting furnaces that produce high temperatures by electric arc.

RS graphite electrode is made from the domestic first petroleum coke and high quality needle coke and widely used in the electric furnaces refractories for production of alloy steels, metal and other refractory nonmetallic materials, etc. Graphite Electrode Application. The graphite electrodes include rp, hp graphite electrode, super high power, uhp and square electrode. The range of diameters covers from 200mm to 700mm.

Welcome to RS, getting the details of the graphite electrodes info and the graphite electrode price. RS can confirm the quality and the quantity. For more: info@graphelectrode.com  .

The production points of graphite electrode nipples have their own particularities. The thermal shock resistance of the nipples and the electrode body’s calcined product and the interface between the aggregate and the asphalt coke are different. In many areas, crack extension and extension easily occur in these areas during graphitization.

When producing ultra high power graphite electrode nipples, while considering the effect of “flatness” on nipple products, it is also necessary to realize that the interface between aggregate and asphalt coke is more widely distributed, and there are more weak areas. There are more potential structural defects between the focal interfaces and other factors.

The surface area of the uhp graphite electrode body is smaller than the nipple blank. The unit volume of the graphite electrode nipple blank is larger than that of the large-diameter electrode body blank. The nipple blank has a relatively large amount of heat dissipation. The temperature difference between the outer periphery of the nipple in series and the core is large. It is necessary to take technological measures to make up for the unfavorable factors such as the relatively large heat dissipation of the nipple blank and the large temperature difference between the periphery and the core.

For the production points of graphite electrode nipples, the conditions that each series of billets should meet are more stringent. To ensure the quality of the nipples, each series of columns must have the same temperature rise rate. The thermal insulation effect and the degree of heat loss of tandem columns in different spatial positions are different.

The quality of graphite electrodes and connectors of Rongsheng Graphite Electrode Factory is reliable. If you want to get the graphite electrode nipple price and manufacturer information of graphite electrodes, please contact us. We will get in touch with you in the shortest time.

With the increase of the proportion of electric furnace steel in the market, the demand for uhp graphite electrode has gradually increased. China’s needle coke resources are further strained, and its prices have been high and highly dependent on imports. This is not conducive to reducing the manufacturing cost of 350mm uhp graphite electrode.

What’s Raw Material used for the UHP Graphite Electorde Production? 

In order to reduce production costs, it is urgent to use Chinese needle coke instead of imported needle coke to produce uhp graphite electrodes. Chinese graphite electrode manufacturer, using Chinese domestic needle coke as raw material, adopts new formula and production process technology to carry out the research and development of φ 350mm UHP Graphite Electrode.

Chinese graphite electrode manufacturers, through optimizing the formula and making full use of the established production process and technical conditions, use Chinese domestic needle coke to produce φ350 mm uhp graphite electrode. It can fully meet the requirements of graphite electrode users.

The Advantages of the Chinese Needle Coke Raw Materials

1.  The Chinese-made needle coke, as the the raw material for the graphite electrodes, which has higher ash content, higher sulfur content, smaller particle strength, and smaller particle tap density.
2.  The graphite electrode produced from the Chinese needle coke raw material has the following physical and chemical properties: high bulk density, equivalent flexural strength, slightly lower elastic modulus, higher ash content, and higher resistivity.
3.  Passed the trial of the steel mill, the graphite electrode has good thermal shock resistance and oxidation resistance performance, which can fully meet the customer’s normal use requirements.
4.  Using uhp graphite electrode produced by Chinese-made needle coke, using large particle formula, the binder adopts medium-temperature modified asphalt or high-temperature modified asphalt, and adopts standard process. The level of the traditional process greatly reduces the production cost and improves the competitiveness of the product, thus achieving the purpose of replacing imported needle coke.

Conclusion

The test of producing φ350 mm uhp graphite electrode by using Chinese-made needle coke was successful. China’s domestic needle-shaped coke raw materials can be popularized for use on medium 400mm and φ450mm uhp graphite electrodes.

It can be seen from the above experiments that using domestic graphite electrode raw materials and through improved production technology, it has been possible to produce 350mm graphite electrode which can meet customer needs. If you have a demand for uhp graphite electrode, please contact us. We will reply to you as soon as possible.

UHP graphite electrodes are becoming more and more widely used. If you have an arc furnace project that requires uhp graphite electrode, or you want to get the latest graphite electrode price. Then, you need to learn more about the graphite electrode market.

First, you need to find the manufacturer of the graphite electrode. There are many graphite electrode suppliers, but not every supplier is a true manufacturer of graphite electrodes. Since the graphite electrode has a complicated production process and a relatively long production cycle, its production workshop covers a large area. A graphite electrode manufacturer that can have a large production workshop must be real.

Secondly, it is the quality of graphite electrodes. Due to the higher requirements of smelting in steel mills, the requirements for the quality of graphite electrodes are also higher. This requires rigorous quality inspection after graphite electrodes are machined. A full set of quality inspection equipment is also the quality guarantee required by the buyer.

In the end, the price of graphite electrodes is much more concerned. Due to the shortage of graphite electrodes in the previous period, the graphite electrode price continued to rise during that period. As this wave recedes, the graphite electrodes price does not seem to be as high as before. As a result, it seems that the demand for graphite electrodes is not as crazy as before. Therefore, it is relatively reasonable to buy graphite electrodes now.

When buying graphite electrodes, the most important thing is to meet the smelting needs of electric arc furnaces. Therefore, sometimes, uhp graphite electrode is not necessarily. However, for arc furnace electrodes with increasing requirements for smelting, it is still recommended to use high-quality uhp graphite electrode.

The relationship between graphite electrodes and steelmaking, is the graphite electrode usage. With the rapid economic development, the demand for special steels in various industries has become more and more extensive, resulting in the rapid development of electric arc furnace steelmaking technology. Large-capacity UHP eaf furnaces and large-scale external furnace refining technologies have become the symbol of modern steel . These electric furnaces use uhp graphite electrodes of different specifications. With the continuous improvement of the arc power and the continuous optimization of the smelting process technology, the physical and chemical indicators of eaf graphite electrodes are getting higher and higher, and the consumption indicators are getting lower and lower.

Judging from the average consumption level of large-scale and large-capacity ultra-high-power electric arc furnaces, the consumption of ton steel electrodes has dropped from an average of 3.5KG / T to 1.2KG / T in the past, while the average consumption of LF furnaces is less than 0.5KG / T . Because graphite electrodes occupy a certain proportion of cost in smelting and consume a large amount, all manufacturers pay great attention to the consumption and use of graphite electrodes, and they are also included in production as an important assessment index. The consumption and use of graphite electrodes in steelmaking.

Factors affecting graphite electrode consumption in smelting

In the steelmaking process, electric arc furnace smelting is divided into roughing and refining, but the graphite electrode transfers electric energy into the electric furnace and converts it into thermal energy to achieve the purpose of heating and melting solid charge. Roughing is an oxidation process with the purpose of melting scrap steel and exhausting harmful gases and impurities. Refining is a reduction process that adjusts steel grade elements and degassing to remove impurities by increasing temperature. It can be seen that electric arc furnace smelting uses graphite electrodes to adjust the furnace temperature to achieve the redox reaction and meet the steelmaking process requirements.

Development trend of smelting technology and electrode demand

The rapid development of electric arc furnaces in the steel industry has become a trend. Its characteristics are large output power, stable power coefficient, power transmission for long arc operation and development in the direction of energy saving. Therefore, the new large electric furnace has great changes compared with the traditional electric arc furnace in the past. Modern electric furnace technology pays great attention to the issue of electric furnace energy. The gas jet gun and automatic carbon oxygen gun can reduce the electrode consumption of 0.3 ~ 0.5KG per ton of steel. With the implementation of hot charging technology, the smelting time is significantly shortened, and the power consumption and electrode consumption are significantly reduced.

Large electric arc furnaces use large-capacity transformers and their overload capacity is 20%. From this point of view, the requirements for graphite electrodes in steel smelting are getting higher and higher, especially for the electrode’s quality balance, conductivity, thermal shock resistance, and oxidation resistance. Because the development of iron and steel has passed the threshold, it is developing in the direction of fine products and special varieties.

Large-scale DC and AC arcs have also been finalized; high-capacity, large-scale, large-scale blast furnaces supporting double-station LF furnaces have become a new development direction. In addition, large-scale furnaces have begun to take shape.

Now the market’s demand for graphite electrodes has developed towards multiple varieties and incremental directions. Among them: the annual demand for UHP graphite electrodes will reach 100,000 T; the annual demand for HP graphite electrodes is at least 180,000 T; the large specifications of HP graphite electrodes φ500MM and φ600MM are also moving in the direction of increase (mainly for furnaces) .

Graphite Electrode Manufacturer

RS graphite electrode manufacturer, according to the production characteristics of graphite electrodes, to provide customers with high quality graphite electrode products, rp/hp/uhp graphite electrodes. If you are in need of EAF Electrode, please contact us!