250mm RP Graphite Electrode

Product Description

HP graphite electrode is the conducting element for electric arc furnaces steelmaking. It is made of petroleum coke, needle coke, coal pitch and produced by a series of strict production processes. High-current lines insert through the graphite electrode port inside the furnace body. This will releases electric energy in the arc furnace to heat the furnace.

Product Specification

Applicable Nipple information

Package

Plywood packing, seaworthy packing 

Transport & Export

Service

Further analysis of graphite electrode fracture in smelting

The causes of electrode breakage in electric furnace smelting operation are quite complex, and great attention should be paid to the following five aspects.

(I) Smelting process

(1) Raw material ratio, electrode below to avoid large materials and non-conductive;

(2) When the "bridge" phenomenon occurs after passing through the well, the long arc operation should be used to avoid the large collapse impact;

(3) the lifting and lifting of the electrode and the small furnace cover must be concentric to avoid scratching and breaking during thermal vibration.

(ii) power transmission system

(1) Determine the initial arc starting gear and lift in sequence (each furnace has at least 3 power supply curves) to avoid excessive current fluctuation and frequent changes of long and short arcs in the furnace resulting in excessive thermal shock;

(2) With the rise of furnace temperature, certain internal stress should be released at the electrode connection, and the current passing through the electrode per unit area should have a gradual rise process after arc initiation, which is the adaptation process of electrode and furnace condition.

(3) overload operation, the overload capacity of the new electric furnace is generally not more than 20%. If the arc current exceeds the rated value of the joint is the most likely to break, when the electrode and furnace conditions adapt to the overload will also operate normally, but there is a joint red phenomenon.

(3) Smelting furnace condition

(1) Feeding and power supply operations are related to the change of furnace condition, but oxygen blowing, nozzle combustion of steam and fuel oil is the key to deteriorating furnace condition. The use of chemical energy reduces the power consumption, but increases the oxidation degree of the electrode surface and top surface. Especially when the negative pressure is too large, the oxidation rate of the electrode surface is accelerated and the surface of the electrode body is conized.

(2) The steelmaking process is the process of slagging. The use of chemical energy increases the stirring power of molten steel and facilitates the production of foam slag. The boiling of molten steel, the thickness of slag layer, the fluidity of slag liquid and the submerged arc effect are not only related to the smelting effect, but also related to the carbon consumption at the bottom of the electrode and the consumption of turning and circumferential surface.

(3) The operation in the furnace deterioration changes frequently, with vibration on the electrode and side-to-side swing. The frequent change of current increases thermal vibration, which not only accelerates the surface consumption of graphite electrode in oxygen-rich environment, but also tests the joint (joint strength).

(iv) Electrode storage and transportation

(1) Avoid contact with liquid medium in the on-site storage electrode, otherwise the scaly pieces will appear after heat.

(2) Avoid close proximity to high temperature heat source in the on-site storage joint, otherwise the joint is easy to melt and flow after being heated.

(v) Electrode quality

For large UHP and HP upper limit electric furnace, the graphite electrode provided must improve the physical quality. (1) Structural defects or insufficient strength must be eliminated, otherwise the joint fracture accident will occur in the first package of smelting material 1~3min of power supply.

(2) The machining accuracy of the end face of the electrode is also very important. If there is a gap, it will generate a breathable phenomenon and be accompanied by local redness. The connection is obviously red about 10min after the power supply. After continuous smelting for 2~3 furnaces, the inner buckle is easy to oxidize and break or fall off.

(3) The problem of tolerance fit must be paid attention to at all times. No matter if it is loose or not in place, as long as there is a gap, it will break or fall off. From the point of use, most of the problems in the parts are caused by tolerance fit.

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