不同脱硫钢的钢包炉精炼工艺优化

Optimization of ladle furnace refining process for different desulfurized steels

针对目前某钢厂1#钢包精炼炉(LF)精炼工艺存在的不合理问题,以Q355ND钢(成品中w(S)≤0.005%)为深脱硫钢、Q235B钢(成品中w(S)≤0.020%)为低脱硫钢进行生产试验。基于罗氏线圈测量交流电原理,计算LF炉电耗,通过对弧流、相电压以及主要工艺参数的分析,研究了氩气流量、造渣料对脱硫效果的影响,并提出适应不同程度脱硫钢种生产的合理工艺。结果表明,Q355ND钢中石灰、化渣剂、合金用量分别为8.50~10.00 kg/t、1.26 kg/t、1.92 kg/t,Q235B钢中石灰、化渣剂、合金用量分别为4.74~5.00 kg/t、1.20 kg/t、1.71 kg/t时,精炼工艺较合理。当钢包透气性较好时,供电期间氩气流量约为380~400 L/min,未通电期间氩气流量约为100 L/min时精炼效果较好。采用两次供电模式,生产效果更佳。

Aiming at the unreasonable problems existing in the refining process of 1#ladle refining furnace(LF)of a steel plant,the production test is carried out with Q355ND steel(w(S)≤0.005%in the finished product)as the deep desulfurization steel and Q235B steel(w(S)≤0.020%in the finished product)as the low desulfurization steel.Based on the principle of measuring alternating current by Rogowski coil and calculating the power consumption of LF furnace,the influence of argon flow and slag-making material on the effect of desulfurization was studied through the analysis of arc current,phase voltage and main process parameters,and a reasonable process adapted to the production of different degrees of desulfurized steel grades was proposed.The results show that the refining process is more reasonable when the dosage of lime,slagging agent and alloy in Q355ND steel was 8.50–10.00 kg/t,1.26 kg/t,1.92 kg/t,and when the dosage of lime,slagging agent and alloy in Q235B steel was 4.74–5.00 kg/t,1.20 kg/t,1.71 kg/t,respectively.When the ladle permeability is better,the argon flow rate during the power supply is about 380–400 L/min,and the unenergized argon flow rate is about 100 L/min.two power supply modes are used,and the production effect is better.