Abstract: The submerged arc performance was not good in the 65 t LF refining process for hard wire steel in certain plant, which resulted in power consumption and w(N) absorption increasing and heating ratio of liquid steel decreasing by 20%. Through analyzing LF refining for hard wire steel, power supply model and slag-forming process were optimized. The fourth voltage grade was used in heating phase. Short arc length was applied to heating in the slag-making stage to ensure slag melting and heating up stable, while middle or long arc length was used in the middle and final stages. The quantity of lime, wollastonite and fluorite was controlled strictly to be 800—900 kg per heat. Reductant (0.6—0.9 kg/t) was put into ladle by little quantity and more frequency in the slag-forming process. If necessary, the blister material was added by 2—3 bags per heat to ensure the refining slag foaming. The results show that the unburied arc heat percentage for hard wire steel refining decreases from 2.5% to 0.3%. The power consumption in hard wire steel refining is 60.32kWh/t, which decreases by 16.92kWh/t. The mass fraction of N absorption in LF process decreases by 8.6×10-6, and the heating rate of liquid steel is 4.1 ℃/min.

Key words: hard wire steel, LF refining, submerged arc performance, power consumption