提高高碳钢连铸方坯等轴晶率的试验研究

Study on increase of equiaxed crystal ratio of high carbon CC billet

为消除和降低高碳钢方坯凝固组织的中心偏析,增加等轴晶率,设计了环缝式水冷水口,开发了水冷水口的在线控制模型和操作平台。在淮钢特钢有限公司150mm×150mm方坯连铸机上进行了降低钢水过热度的工业试验。结果表明:环缝式水冷水口装置可操作性强,可实现钢水浇铸温度的闭环控制;冷却介质在线调控系统可以满足浇铸参数波动的需要,正常连铸工艺下稳定拉坯持续4h,浇铸钢水约400t,降低钢水过热度约14℃,提高铸坯等轴晶率10%以上。

To eliminate or reduce the central segregation and increase the equiaxed crystal ratio a circular seam water cooling nozzle is designed and an on-line control model and operating platform of the water cooling nozzle is developed.The industrial scale experiments on reduction of hot metal overheat is carried out at the 150 mm×150 mm billet continuous caster in the Special Steel Co.,Ltd of Huai Steel Corporation.Results show that the circular seam water cooling nozzle is featured of high operability and closed loop control of the casting temperature of the hot metal can be realized and the cooling medium on-line control system can meet the requirements of the fluctuation of the casting parameters and stable drawing can last for 4 hours under the normal continuous casting process conditions and cast about 400 t hot metal and reduce the overheat of the hot metal by14 ℃ and raise the equiaxed crystal ration by over 10%.