Factors Affecting Electric Arc Furnace Electrode Consumption

Electric arc furnace electrode consumption refers to the loss of electrode materials during the arc furnace steelmaking process. The main influencing factors include current intensity, smelting time, operation method and charge composition.

The electrode material is usually graphite electrode, and its consumption directly affects the steelmaking cost and production efficiency. Therefore, optimizing the use of electrodes, such as selecting suitable electrode materials and controlling operating parameters, is crucial to reducing costs.

Factors Affecting Electric Arc Furnace Electrode Consumption

Mainly include process operation, raw material characteristics, equipment conditions and the quality of the electrode itself. The following are the main influencing factors and their mechanisms of action:

1. Process operation factors

• Current intensity and arc length

High current or long arc will cause the electrode tip temperature to be too high, aggravating oxidation and sublimation (direct consumption).

Arc instability (such as frequent fluctuations) may cause electrode breakage or peeling.

• Smelting stage control

Melting period: Graphite electrode consumption is the largest (arc is exposed to air and oxidation is intense).

Oxidation period and reduction period: Oxygen blowing operation will accelerate the oxidation of the electrode side wall; if carbon powder is used in the reduction period, consumption may be reduced.

• Power-on time

The longer the smelting cycle of the electric arc furnaces, the longer the electrode is exposed to high temperature, and oxidation and thermal stress damage accumulate.

2. Raw materials & charge characteristics

• Charge composition and state

High melting point or refractory materials (such as high chromium steel) require longer power-on time, which increases the consumption of arc furnace electrodes.

Low charge density (such as light and thin materials) leads to unstable arc and frequent electrode movement.

• Impurities and humidity

Damp or volatile (oil, water) charge may cause arc flash and electrode cracking.

3. Electrode quality & type

• Graphitization degree

High-purity, high-density graphite electrode have strong oxidation resistance and low consumption rate.

Ordinary electrodes are prone to oxidation and thermal expansion cracking due to high porosity.

• Electrode diameter and connection quality

Insufficient diameter will lead to excessive current density and local overheating.

Loose threaded connections may cause joint breakage or additional wear.

4. Equipment & external conditions

• Furnace atmosphere

Oxygen-rich environment (such as oxygen blowing to assist fluxing) significantly accelerates oxidation of the electrode side wall (C + O₂ → CO₂).

When the melting furnace body is poorly sealed, air intrusion exacerbates oxidation.

• Cooling system efficiency

Insufficient cooling of the electrode holder will lead to thermal stress concentration and increase the risk of transverse cracks.

• Mechanical vibration and collision

Mechanical impact during electrode lifting or furnace tilting may cause electrode breakage or surface peeling.

5. Other factors

• Electrode adjustment system accuracy

Automatic adjustment system response delay may cause short circuit between electrode and molten pool, causing end damageThe factors affecting electric arc furnace electrode consumption involve many aspects, mainly including process operation, raw material characteristics, equipment conditions and electrode quality. 

Measures to Reduce Graphite Electrode Consumption

1. Optimize the process: shorten the electric arc furnaces melting time, reasonably control the oxygen blowing amount, and stabilize the arc length.

2. Raw material pretreatment: dry the charge and increase the stacking density.

3. Electrode maintenance: select high-quality electrodes (such as ultra-high power graphite electrodes) and regularly check threaded connections.

4. Equipment improvement: strengthen furnace sealing and optimize cooling system.

5. Intelligent control: use electrode intelligent adjustment system to reduce short circuit risk.

Electrode consumption is an important part of the cost of steelmaking electric furnace (accounting for about 5% to 10% of production cost). By comprehensively regulating the above factors, the consumption rate can be effectively reduced and economic benefits can be improved.