UHP700 cracking analysis and solution for EAF smelting end face

For UHP700, the current during the smelting process is 82000A-123000A, and its current density is 20-30A/CM². For UHP700 electrode, its cross-sectional area is 3846M². When UHP700 electrode is working with a current of 3845M², and while the electrode end is oxidized to a diameter of 450mm,its cross-sectional area is 1590M² . If the current not changed, with the decrease of cross-sectional area of ​​the electrode, the current density will increase, and resulting in a larger electrode bearing capacity, with the addition of the strength of electrode arc at the bottom of the arc furnace, the external and internal force of the electrode increase. Therefore, cracks are easy to appear, and under normal circumstances, it will not break or fall off. In this case, in order to increase the production capacity and output, if the current reaches the highest value of 130000A or above, the bottom electrode will fall off, which is the cause of the crack.

 

2. Reasons affecting electrode consumption: three-phase imbalance, large transformer capacity, high secondary current/voltage, excessive oil consumption, and high oxygen consumption.

 

3.Suggestion: During the smelting process, current increases slowly in order to reduce consumption. During smelting process, the electrode end gradually become thinner, the end sublimates and the slag erodes the electrode and melts (invades the molten pool). Of course, the electrode consumption has a lot to do with the design characteristics and furnace conditions of the electric arc furnace. And during this period, do not increase the current suddenly, which can effectively reduce the electrode consumption.