Abstract: Based on statistics of process data of IF steel (/% : ≤ 0.002 5C, ≤ 0. 005Si, 0. 01 ~0, 12Mn, ≤ 0. 020P, ≤ 0. 010S, 0. 02 ~0. 04Als, 0. 03 ~0. 05Ti) in steelmaking process, the effect of oxygen content in liquid at Ar station and amount of adding aluminium in RH decarburization period on T[O] , and the effect of alloys adding procedure, top slag modified treatment and shielding casting process on cleanliness of liquid are analyzed. Research results show that the measures including proper increasing the BOF end oxygen content in liquid and temperature of liquid, extending the interval time between Al and Fe-Ti addition, top slag modifying treating and shielding casting process are available to increase the cleanliness of liquid. It is obtained by commercial production that with the average temperature of liquid at initial RH refining increasing by 2. 4 °C , controlling BOF tapping slag amount to decrease the thickness of top slag layer from original 。80 mm to 60 ~75 mm as a result during RH decarburization process the adding aluminium heats decreasing by original 36% to 3% , and with top slag modification to decrease the (FeO + MnO) from original 22% to 17% and increase the continuous-continuous casting heats from 8 heats to 10 heats, the T[O] in liquid in tundish decreases form 37. 4 x 10 ^-6 to 21. 6 x 10^-6 to obviously increase the cleanliness of liquid.

摘要： 基于IF钢（/%:≤0.0025C,≤0.005Si,0.01～0.12Mn,≤0.020P,≤0.010S,0.02～0.04Als,0.03～0.05Ti）冶炼过程工艺数据的统计,分析了Ar站钢水氧含量和RH脱碳期加铝量对钢中T[O]的影响,以及合金加入时机,顶渣改质处理和连铸保护浇铸对钢水洁净度的影响。研究结果表明,适当提高转炉终点氧含量和温度、延长加铝和钛铁之间的时间间隔、顶渣改质处理、连铸保护浇铸等方法可有效提高钢水洁净度。生产结果得出,通过RH进站钢水温度平均提高2.4℃,通过控制转炉下渣量,使顶渣厚度由≥80 mm降至60～75 mm,使RH脱碳过程加铝炉次由原36%降至3%,通过顶渣改质,使（FeO+MnO）由原22%降至17%,连浇炉数由8炉提高到10炉,连铸中间包T[O]由37.4×10^-6降低至21.6×10^-6,钢水洁净度得到了显著提高。