马氏体不锈钢连铸时水口结瘤的工艺研究

Study on Process of Removing Nozzle Clogging during Continuous Casting of Martensitic Stainless Steel

通过对马氏体不锈钢连铸时结瘤物的成分分析,确定结瘤物的成分主要为Al2O3,同时对结瘤堵塞现象进行热力学及动力学分析,得出结瘤原因为悬浮于钢液中未排除的以及二次氧化钢水中[Al]形成Al2O3夹杂逐步沉积在水口壁上所致。在清楚结瘤堵塞的机理后,通过采取净化钢液和防止二次氧化的手段来破坏结瘤形成的必要条件,并在大生产中逐步改进工艺最终消除结瘤现象。

Analyzing the compounds of the clogging during continuous casting of martensitic stainless steel, it was concluded that the main composition of the clogging was Al2O3, and analyzing the clogging phenomenon from the aspect of thermodynamics and kinetics, it was concluded that Al2O3 inclusions suspended in the molten steel and formed by [Al] in the secondary oxidized molten steel precipitated gradually on the nozzle wall and caused the clog- ging phenomenon. On the basis of understanding of the clogging mechanism, some measures including purifying molten steel and preventing the secondary oxidization were adopted to break the essential condition for forming the clogging, and process was improved step by step in the production to eliminate the clogging phenomenon finally.