260 t转炉-RH流程IF钢DC06顶渣改质剂优化生产实践

为保证精炼渣有较好的脱氧与吸附夹杂物的能力,采取5种顶渣改质剂对无间隙原子钢（IF钢）转炉出钢钢包顶渣进行改质工业试验。并采用电感耦合等离子体原子发射光谱法（ICP-AES）对渣成分进行检测,运用FactSage软件对精炼渣粘度进行计算。研究结果表明,5种改质剂改质后,真空循环脱气（RH）出站时,5炉精炼渣中TFe含量控制在6.46%~7.76%,钙铝比（CaO）/（Al₂O₃）控制在1.60~1.86,1 600 ℃时精炼渣粘度在0.057~0.068 Pa·s,导致夹杂降级比为 2.10%~12.86%,3号改质剂（48.5% Al-10.2% Al₂O₃-18.1%CaO-6.0%SiO2-8.0% CaF₂）综合性能最合适。采取转炉出钢碳由改进前的0.032%增大至0.045%,优化改质剂用于生产后,RH进站精炼渣中全铁（TFe）控制在7.13%,RH出站渣中FeO控制在5.52%,热轧时因顶渣改质造成的废次比为0.071%,降低了20.2%。 

Optimization and Production Practice of Top Slag Modifier forIF Steel DC06 with 260 t BOF-RH Flowsheet

In order to ensure that the refining slag has better deoxidation and absorption ability of inclusions, the five top slag modifiers are used to carry out industrial tests on the top slag of the converter tapping ladle of IF steel. ICP-AES (Induction Coupling Plasma-Atomic Emission Spectroscopy) is used to detect the slag composition and FactSage software is used to calculate the viscosity of refining slag. The results show the vacuum circulation degassing (RH) is out the station, after 5 kinds of madifiers are used, that the content of TFe in the refining slag of 5 heats is controlled at 6. 46% ~7. 76%, the ( CaO)/(Al₂O₃) ratio is 1. 60 ~ 1. 86 at 1 600 ℃, the viscosity of refining slag is 0. 057 ~ 0. 068 Pa ·s, the degradation ratio of degradation caused by inclusions is 2. 10% ~ 12. 86%, and No. 3 modifier (48. 5% Al-10. 2% Al₂O₃-18. 1% CaO-6. 0% SiO2-8- 0% CaF₂) has the best comprehensive performance. After the carbon content in the steel increases to 0. 045% from 0. 032% during converter tapping, and the optimized modifier is used in production, the TFe content in slag before RH is controlled at 7. 13% , and the FeO content in slag after RH is controlled at 5. 52% and during hot rolling, the ratio of off-and sub-quality products with top slag modification is 0. 071%, which is reduced by 20. 2%.