Direct losses caused by broken graphite electrodes during smeltingGraphite electrode breaking is a common phenomenon in all electric furnace smelting, and it i

Direct losses caused by broken graphite electrodes during smelting

Graphite electrode breaking is a common phenomenon in all electric furnace smelting, and it is also the most important factor affecting consumption. In a complex environment, continuous consumption and occasional breakage is normal, but continuous breakage is abnormal. The reason is related to many factors. Generally speaking, it can be divided into: artificial breakage and mechanical breakage. Man-made fractures mainly include: bumps and scratches during lifting, improper connection or improper method, improper sliding in the flat holder, hard collision or poor transmission control sensitivity, etc. In addition to mechanical failures in mechanical breaking, electrode quality problems and operational problems often coexist and are difficult to distinguish. The following phenomena mainly exist.

(1) The electrode body is broken

One is that the electrode may have structural defects and may be of low strength; the other is that the short-arc operation is still in the smelting process and there is a large side impact force of the collapse; the third is that the three-phase electrode on the furnace is seriously not vertical and there is slag hanging in the furnace. Or the phenomenon of scraping the furnace cover and so on. The sound is very crisp and loud when broken.

(2) The bottom of the electrode body is broken

The first is that the structure of the electrode end is loose or has dark lines, the joint and the hole are not matched properly, or the material difference does not match the linear expansion coefficient; the second is that the phase electrode is not concentric, the electrode stroke is too long or the lifting is not sensitive; the third is the fabric in the furnace is unreasonable , There are non-conductive objects under the electrode. When it is broken, the sound is not loud but the tilt is heavier.

(3) The joint is broken and is irregular

One is that the taper of the joint is different or the ellipse of the joint hole is too large; the second is that the dust in the hole during the connection causes excessive contact resistance, and the joint thread is locally oxidized and too fast; the third is that the electrode is not connected in place and the torque requirement is not met, resulting in loosening ; Fourth, the holder is tilted, the electrode is not concentric with the furnace lid hole, etc. The sound is crisp and small when broken.

(4) The joint breaks are regular phenomenon

The first is that the quality of the joint itself varies greatly, and the strength of the joint cannot meet the requirements of the smelting furnace; the second is that the electrode hole and the joint tolerance are not properly matched or the connection torque does not meet the requirements, and the return is generated; the third is that the secondary current fluctuation range in the power supply is too large or There is a sudden increase phenomenon, and the maximum instantaneous current far exceeds the rated value by more than 1.2 times; fourth, the thermal shock generated when the output power is too large is also too large, and the electrode connection is red and the resistance is too large. The sound becomes muffled when broken.