In the process of electric furnace steelmaking, the tip of graphite electrode volatilizes due to the high temperature of electric arc, and the end is shortened continuously.
In the process of electric furnace steelmaking, the tip of graphite electrode volatilizes due to the high temperature of electric arc, and the end is shortened continuously. The other part is the side wall consumption caused by oxidation and slag erosion. The side wall consumption can be reduced by spraying or fusing a layer of Al based cermet anti-oxidation coating on the surface of graphite electrode. In addition to the anti-oxidation coating method, solution impregnation method, self-healing method and carbon ceramic composite method are also under development.
The oxidation resistant coating must meet the following requirements:
It can withstand high temperature without melting, and the decomposition temperature of coating is above 1850 ℃.
It has good bonding with the surface layer of electrode and has similar coefficient of thermal expansion.
The conductivity is higher than that of graphite electrode matrix.
It should have certain mechanical strength.
It has no adverse effect on smelting operation and molten steel quality.
Compared with the graphite electrode with the same quality, the electrode consumption per ton of molten steel can be reduced by 20% - 40%, and the power consumption of steelmaking can be reduced by about 15%. Moreover, due to the low resistance of the coating, the current density through the electrode can be increased and the electrode diameter can be reduced.
The results show that the diameter of graphite electrode with oxidation resistance coating is 300-500mm, the resistivity is less than 6.5x10-6 μ Ω· m, the coating thickness is 0.5-1.0mm, and the coating weight gain is 1.5-2.0kg.
Post time: Aug-17-2021