摘要
通过建立大方坯结晶器内钢液流动、传热、凝固和夹杂物运动耦合模型,研究了浸入式水口结构对结晶器内钢液流动和夹杂物运动的影响,比较了5种不同孔数的水口对应的夹杂物上浮、下沉以及坯壳吸附的比率和速率。研究结果表明:浸入式水口的结构很大程度上决定了结晶器内钢液的流动方式,进而决定了小颗粒夹杂物的运动轨迹。从水口底孔出来的射流中向上回流至液面部分的流股以及从侧孔出来的射流形成的螺旋上升的流股是促进夹杂物上浮的主要动力。只含侧孔的四孔型和双孔型水口在夹杂物去除方面能力最强,对于50μm的小颗粒夹杂物去除率分别为25%和17%;而带底孔的水口(包括单孔型、三孔型和五孔型水口)去除率基本在10%以下。此外,对于含底孔的水口,铸坯内部夹杂物相对较多,而对于只含侧孔的水口,铸坯表面附近夹杂物相对较多。
By developing the coupled model including the liquid steel flow, heat transfer with solidification, and inclusions movement in the mold, the effect of the structure of submerged entry nozzle （SEN） on the liquid flow and inclusions movemcnt were researched. The features were compared including the amount and time of inclusions floated up to the steel surface, entrapped by the solidification front, and sunk to the model outlet by using five kinds of SENs with different port number. Results showed that the structure of SEN influenced the flow pattern of the liquid steel in mold greatly, which decided the trajectory of small inclusions. Two kinds of upward flow primarily promoted the flotation of inclusions. A part of the downward jet from the bottom port of the SEN flowed up to the surface, and a part of the spiral flow caused by the jet from the side ports also went upwards. The SEN with four or two side ports did better for inclusions removal, and about 25% and 17% of 50 μm inclusions were removed respectively, while the inclusions removal rates for the SENs with bottom ports （such as SENs with one, three, or five ports） were all below 10%. In addition, there were more inelusions in the center than beneath the surface of the strand when using the nozzle with a bottom port, and the result was on the contrary when using the nozzle only with side ports.
出处
《上海金属》
CAS
北大核心
2012年第5期51-56,共6页
Shanghai Metals
关键词
浸入式水口
大方坯
结晶器
夹杂物运动
Submerged Entry Nozzle, Bloom, Mould, Inclusions Movement
