Abstract: By the method of using a full-process system sampling, a systematic analysis and research on the evolution of the oxygen content and the inclusion characteristics in a 20CrMnTi gear steel produced in the process of 120 t BOF-LF- VD-CC have been carried out. The experimental results show that using the technology of aluminum deoxidation and the high-basicity [ (CaO)/(SiO₂) =3. 8 ~7 ] reduction slag, the T[O] in the slab can be less than 20 x 10^-6 ； the average T[O] of liquid in tundish gas increases by 6 x 10^-6 ； during the steelmaking process of gear steel, the inclusions in steel have completed the transformation from Al₂O₃→ Al₂O₃ -MgO—;Al₂O₃ -CaO-MgO.

摘要： 采用全流程系统取样的方式,对120 t BOF-LF-VD-CC工艺生产20CrMnTi齿轮钢中氧含量和夹杂物特性的演变规律进行系统的分析和研究。实验结果表明,采用铝脱氧和高碱度[（CaO）/（SiO₂）=3.8～7]还原渣工艺,能使铸坯中T[O]低于20×10^-6;中间包钢水中平均T[O]增加6×10^-6;齿轮钢冶炼过程中,夹杂物完成了Al₂O₃→Al₂O₃-MgO→Al₂O₃-CaO-MgO的转变。