The reasons and solutions for the breakage of UHP graphite electrodes during EAF and LF smelting

The consumption of UHP electrodes in electric furnace production is about 3%-5%. The electrode consumption mainly includes oxidation, breakage, end sublimation, and slag erosion causing electrode melting. The digestion of electrodes is closely related to the design characteristics of the arc furnace, as well as the quality of furnace burden and electrode itself. The reasons for breakage during the smelting process of UHP300, 350, 400, and 450 are mainly as follows:

1. Non-conductive substances in scrap steel in the furnace.

2. Scrap steel blocks are too large.

3. Transformer capacity is too high.

4. Three-phase imbalance.

5. Excessive vibration.

6. Clamp pressure is too high or too low.

7. Secondary voltage and current are too high.

 

To solve the problem of electrode breakage: reduce damage caused by mechanical external forces, collapse material inside the furnace, and improper operation; when charging materials into the furnace, large pieces of steel should be placed on the lower layer as much as possible, and scrap materials should be evenly distributed inside the furnace; avoid non-conductive materials in scrap steel from accumulating directly below the electrode to prevent affecting electrical conductivity and causing electrode breakage; maintain good condition of tilting system to keep balance during tilting process; prevent steel slag or foreign objects from embedding into electrodes or joints that may affect connections; use compressed air to clean before use.