Abstract: The variations of the total oxygen content, the amount, size and morphology of inclusions in three heats 0. 6% C steels were studied systematically by sampling of molten steel and slag during LF refining and continuous casting. The results show that the total oxygen content of three heats 0. 6% C steel is about 0.007 0% in start of LF refining, the total oxygen content of three heats 0.6% C steel is reduced slowly and the total oxygen content in the casting blank is reduced to less than 0. 003% during start of LF refining→ after calcium treatment→end of soft argon stirring→ tundish casting→ casting slab. In start of LF refining, the inclusions of three heats 0. 6% C steel are mainly SiO₂-MnO-(Al₂0₃ ) inclusions, which are the deoxidized products of silicon and manganese. After calcium treatment, the inclusions in the steel are transformed into CaO-SiO2 -Al₂O₃ -MgO whose main components are CaO + MgO 20% ~40% , SiO2 20% ~40% , Al₂O₃ 30% ~50%. Due to the secondary oxidation of molten steel during tundish pouring, the total oxygen content of molten steel and the a¬mount of SiO₂-MnO-( Al₂O₃) of the secondary oxidation products in 0. 6% C steel tundish have increased significantly.

摘要： 通过LF精炼和连铸过程钢水和炉渣取样,对3炉60钢冶炼各个阶段的T[O]显微夹杂物的数量、尺寸及类型的变化进行了系统研究。结果表明,在LF进站时,3炉60钢中T[O]为0.007 0%左右;从LF进站→钙处理后→软吹结束→中间包浇注→铸坯,3炉60钢中T[O]总体呈现缓慢降低的趋势,其铸坯中T[O]降到0.003%以下。LF进站时,3炉60钢中夹杂物以硅锰脱氧产物SiO₂-Mn0-（Al₂O₃）复合夹杂为主;经钙处理后,其钢中夹杂物转变为CaO-SiO₂-Al₂O₃-Mg0系复合夹杂,该复合夹杂物的主要成分为CaO+MgO 20%～40%,SiO₂ 20%～40%,Al₂O₃ 30%-50%。由于中间包浇注过程钢液存在明显二次氧化,导致60钢中间包内钢水T[O]和二次氧化产物SiO₂-MnO-（Al₂O₃）夹杂数量明显增加。