In EAF steelmaking, a “transverse fracture” of graphite electrodes cannot simply be attributed to a single cause; it usually requires judgment based on the fracture location and on-site operating conditions. It may be caused by an inherent quality problem of the electrode itself or by improper furnace operation, and both have clear fracture mechanisms.
How to make a preliminary judgment based on fracture characteristics
If the fracture is in the electrode body (not at the joint)
This situation tends more toward electrode quality or thermal stress issues:
- Quality defects: Internal transverse cracks, threaded socket defects, or insufficient bulk density and strength in the electrode body.
- Thermal shock damage: Poor thermal shock resistance of the electrode, with deep cracks forming at the end under the high temperature of the arc, leading to transverse fracture.
- Thermal stress: Under high-power operation, local heating of the electrode generates enormous thermal stress that exceeds the material strength and causes cracking.
If the fracture is at the joint or near the holder
This situation tends more toward operational or equipment problems:
- Broken by collapse: Scrap forms a “bridge” and then suddenly collapses, directly breaking the electrode or causing a huge lateral impact; the fracture is often near the clamping point.
- Improper clamping: The holder is not clamped on the designated white line area, foreign matter on the clamping surface causes stress concentration, or non-vertical electrode connection generates additional bending moment.
- Joint problems: Although joint breakage often originates from quality issues (such as poor machining accuracy or high electrical resistivity), non-standard joining operations (such as incomplete cleaning or improper torque) can also directly lead to loosening or breakage. Some data show that in EAF steelmaking, more than 80% of electrode usage accidents are related to joint breakage or loosening.
Recommended troubleshooting steps
- Examine the fracture surface: Check whether it is a clean brittle fracture (leaning toward quality/thermal stress) or a fracture with signs of wear and loosening (leaning toward operation/clamping).
- Check the records: Review the operations before the fracture to see whether there were abnormalities such as scrap collapse, oxygen blowing disturbance, prolonged overload, or short circuit.
- Compare with standards: Verify whether indicators such as bulk density, flexural strength, and electrical resistivity of the electrode and joint meet the requirements for the current furnace type (such as ultra-high power).
Post time: Oct-20-2026