连铸工艺参数对大圆坯凝固组织影响的数学模拟  

Simulation on the influence of continuous casting process parameter on solidification structure of large round billet

作　　者：孙涛[1] 岳峰[1] 郭春[1] 李瑛 马忠存 郭鑫 

机构地区：[1]北京科技大学冶金工程研究院,北京100083 [2]北满特殊钢有限公司,黑龙江齐齐哈尔161041

出　　处：《炼钢》2015年第6期23-28,共6页Steelmaking

摘　　要：基于PmcAsT软件研究了中间包钢水过热度、连铸坯拉坯速度、连铸机二冷强度等连铸工艺参数对大断面圆坯凝固组织的影响规律。研究结果表明：结晶器电磁搅拌电流为300A、频率为3Hz条件下，随着过热度的降低，连铸坯中心等轴晶率显著增加，过热度由49℃降至29℃时，过热度每降低10℃，铸坯中心等轴晶率增大4％左右；拉速由0．16～0．20m／rain每增加0．02m／min，二冷强度由标准水量的1．5～0．5倍每降低0．5倍，连铸坯中心等轴晶率有所增加但均不显著，均为1.5％左右。降低过热度能够显著细化凝固组织晶粒，而改变拉速和二冷强度对于细化凝固组织晶粒作用不明显。对于调整连铸工艺参数而言，提高连铸坯中心等轴晶率和细化凝固组织晶粒的最有效办法是降低中间包钢水过热度。A mathematical simulation was conducted using the ProCAST software for the solidification process of the large round billets. The effect of liquid steel superheat in tundish, casting speed and secondary cooling intensity on solidification of continuous casting billet were studied. The results showed that under the condition of mold electromagnetic stirring （EMES） with 300 A current and 3 Hz frequency, the equiaxial crystal ratio of casting billet increased significantly with the reduce of the degree of superheat, from 49 ℃ to 29℃, and the equiaxial crystal ratio increases by 4 % roughly for every 10 ℃ drop in the superheat. The equiaxial crystal ratio of casting billet increased insignificantly when casting speed increased for every 0. 02 m/min up from 0. 16 m/min to 0. 20 m/min and secondary cooling intensity reduced for every 0. 5 times from 1.5 times to 0.5 times of the standard water flow rate, only roughly 1.5 %. The grain sizes of solidification structures were refined significantly with decrease in superheat, but the changes of the casting speed and secondary cooling intensity had little effects on it. So reducing the superheat of the steel in tundish is the most effective way to improve the equiaxial crystal ratio and refine the grain size of continuous casting billet among the continuous casting process parameters.

关 键 词：35钢 大断面圆坯 凝固组织 PROCAST 数学模拟 

分 类 号：TF777.4[冶金工程—钢铁冶金]