镀锡基板炼钢过程夹杂物控制工艺技术研究

Research on inclusion control technology in the steelmaking process of tinplate

通过Factsage热力学软件计算,研究不同w(CaO)/w(Al 2O 3)比值对炉渣物化性能的影响,确定低FeO活度、高CaO活度、低Al 2O 3活度的渣系组成。开发转炉部分脱氧出钢工艺技术,工业应用显示可降低转炉出钢过程温降约7.7℃,且脱氧产物为易于去除的大尺寸簇状Al 2O 3类夹杂物。通过转炉部分脱氧出钢工艺、出钢后和RH破空后两次炉渣改质工艺的协同作用,RH真空处理后,RH炉渣的氧化性显著降低,TFe质量分数稳定控制在4%~6%,每100 mm 2连铸成品中大尺寸夹杂物(20μm以上)的数量密度显著降低,从2.2个降低到不超过1个。

The effect of w(CaO)/w(Al 2O 3)on the physical and chemical properties of the refining slag was investigated through the Factsage thermodynamic software,and the slag composition was determined which had low FeO activity,high CaO activity and low Al 2O 3 activity.The semi-killed tapping technology was developed,after industrial application,the temperature drop of converter tapping was abled to lower about 7.7℃,and the deoxidation products were large scaled-clustered Al 2O 3 inclusions which were easily removed from molten steel.Though the synergistic effect of the converter semi-killed tapping process and two slag upgrading processes after steelmaking and RH vacuum break,the TFe mass fraction of slag can be controlled to 4%–6%,and the quantity density of the large scaled inclusions(more than 20μm)in tinplate has significantly decreased,from 2.2 per 100 mm 2 before to less than 1 per 100 mm 2.