中碳钢连铸过程中碳质水口结瘤现象的研究

Investigation on Al_2O_3-C based nozzle clogging during billet continuous casting of mid-carbon steel

研究了中碳钢连铸方坯生产过程中浸入式水口发生结瘤现象的原因和防止结瘤的方法。用SEM对水口结瘤物成分进行了分析,对采集的钢包、中间包及铸坯的钢样中夹杂物进行了观察,并对整个铸坯断面进行了定氧分析及对水口结瘤情况进行了数字模拟。结果表明,水口处结瘤物的来源主要是钢中Al2O3夹杂物和钢液对钢包和中间包内衬的侵蚀,并提出了解决中碳钢连铸水口结瘤问题的办法。

The cause to the clogging of the Submerged Entry Nozzle （SEN） during billet continuous casting of mid carbon steel as well as the preventative measures have been investigated. The chemical compositions of the clogging materials are analyzed and inclusions in steel samples out of the ladle, tundish and billet observed by the optical microscope and SEM and the total oxygen content across the whole section of the billet quantitatively measured and the nozzle clogging condition numerically simulated. Results show that the clogging materials around the nozzle mainly originate from alumina inclusions and Al2O3-MgO spinels in steel as well as the produce out of the hot metal corrosion on the inner lining of the ladle and tundish and in the meanwhile solutions to the nozzle clogging of the mid carbon steel put forward accordingly.