Abstract: With 100 t LF original refining end slag (/% : 53. 8CaO, 8. 16MgO, 16. 6SiO2, 17. 45Al₂O₃, 1. 44TFe, 1. 26S, ZG. 08) to improved refining end slag (/% : 51.3CaO, 6. 36MgO, 25. 0SiO₂, 6. 73Al₂O₃, 2. 96TFe, 0. 76S, R2. 05) by decreasing the basicity and Al₂O₃ content in slag, the equivalent number of inclusions in steel 65Mn (/% : 0. 63 ~ 0. 65C, 0. 19 ~ 0. 22Si, 0. 92 ~ 0. 96Mn, 0. 005 ~ 0.006S, 0. 021 ~ 0. 022P, 0.003 5 ~ 0.003 7T [O]) decreases from 18. 4 incluisons/mm² to 11. 3 inclusions/mm², and the average diameter of inclusions reduces from 8. 4 μm to 4.5 μm. As compared with original refining slag by using optimized refining slag the number of Al₂O₃ per mm² in steel 65 Mn at LF end refining decreases from 5. 9 to 1. 7; and the Al₂O₃ content in CaO-SiO₂-Al₂O₃ and CaO-SiO₂ -Al₂O₃ -MgO compound inclusions decreases from 38. 3% ~ 44. 7% to 17. 5% ~ 28. 7% ； and the reject rate of coil due to unqualified B series Al₂O₃ inclusion decreases from 6% to 3%.

摘要： 100 t LF原精炼终渣（/%:53.8CaO,8.16MgO,16.6SiO,17.45Al₂O₃,1.44TFe,1.26S,R3.08）优化成终渣（/%:51.3CaO,6.36MgO,25.0SiO₂,6.73Al₂O₃,2.96TFe,0.76S,R2.05）后,通过降低碱度和渣中Al₂O₃含量,65Mn钢（/%:0.630.65C,0.19~0.22Si,0.92~0.96Mn,0.005~0.006S,0.021~0.022P,0.0035~0.0037T[O]）中的夹杂物当量个数由18.4个/mm²减少到11.3个/mm²,其平均直径由8.4μm减小到4.5μm。相比原精炼渣系,采用优化渣系的65Mn在LF出站时的钢中Al₂O₃由5.9个/mm²降低到1.7个/mm²;其CaO-SiO₂-Al₂O₃和CaO-SiO₂-Al₂O₃-MgO复合夹杂物中Al₂O₃含量由38.3%44.7%降低到17.5%28.7%。B类Al₂O₃夹杂物不合格的卷数由6%降至3%。