Abstract: The oxygen content in concasting billet has been controlled less than 20×10-⁶ in condition of non-vacuum treatment with 55 t LD-60 t LF melting flow sheet at Shijiazhuang Iron and Steel by the operation measures such as controlling LD blowing end-point carbon:low carbon steel 0.08%～0. 10%C;medium carbon steel 0. 10%～0. 15%C and high carbon steel ≥0.20% C,strengthening pre-deoxidation at steel tapping of LD,controlling slag tapping rate up to 98%, controlling Als 0.020%～0.035% during LF refining,to ensure refining(FeO)≤0.5%,feeding CaSi wire,50~80 L/ min soft blowing argon time ≥7 min,protective casting in whole process,using high efficiency holding and absorbing slag agent,and constant casting operation

Key words: LD-LF-CC,Clean Steel,Pre-Deoxidation, Protective Casting

摘要： 控制LD(氧气顶吹转炉)吹炼终点C-低碳钢0.08%～0.10%C、中碳钢0.10%～0.15%C、高碳钢 ≥0.20%C;通过LD 出钢时强化预脱氧，控制出渣钢下渣率达98%,控制LF精炼Als为0.020%～0.035%,保证精炼渣中(FeO)≤0.5%,喂CaSi线，50~80 L/min软吹氩时间≥7min以及全程保护浇注；中间包采用高效保温吸渣剂及稳定连铸操作等工艺措施，使石钢55t转炉-60tLF 冶炼流程在不进行真空处理的工艺条件下，连铸坯中氧含量控制在20×10-6以下