超低磷钢冶炼试验研究

Experimental Research on Ultra-low Phosphorous Steel Smelting

在实验室15 kg真空感应炉上研究Li2O、Na2O、K2O、CaF2添加试剂对铁水脱磷效果影响的基础上,在120t顶底复吹转炉上的脱磷期通过添加含Li2O、Na2O、K2O的锂云母矿进行了超低磷钢的生产试验。实验室研究结果表明,脱磷渣中添加15%Li2O时铁水中的磷可由0.109 4%降到0.003%的水平,脱磷率高达97.3%,脱磷开始0～5 min时间内表观脱磷速率达到0.021%/min;120 t转炉工业试验表明,在转炉入炉铁水[P]含量0.109 9%条件下,半钢[P]平均0.035%,半钢脱磷率平均68.1%,转炉终点[P]平均0.005 8%,最低0.003%,终点脱磷率平均94.8%,最高97.3%。

After investigating the influence of some additives（i.e.,Li2O,Na2O,K2O,CaF2） on hot metal dephosphorization in 15 kg vacuum induction furnace,production test in 120 t top and bottom combined blown converter was carried out to smelt the ultra-low phosphorous steel through adding lepidolite ore which contains Li2O,Na2O and K2O during the dephosphorization period.The experiment results of 15 kg vacuum induction furnace show that through adding 15% Li2O to the dephosphorization slag,the phosphorus mass fraction was decreased from 0.109 4% to 0.003% with a dephosphorization ratio up to 97.3%,and the apparent dephosphorization rate reach to 0.021%/min within 5min since the beginning of dephosphorization.Furthermore,in the production test,the average phosphorus mass fraction and the average dephosphorization ratio of semi-steel are 0.035% and 68.1% with the original phosphorus content in the molten iron charged into converter at 0.109 9%.In addition,the average phosphorus content and the average dephosphorization ratio at the BOF endpoint are 0.005 8% and 94.8%.The corresponding minimum phosphorus content and the maximum of dephosphorization ratio at the BOF endpoint are 0.003% and 97.3%,respectively.