一种新的旋流连铸技术——电磁旋流水口

日本及中国的学者研究表明，在连铸过程中浸入式水口内的旋转流动可以有效改善结晶器内的流体流动状态并提高钢坯的表面和内部质量。笔者提出一种新的旋流连铸技术，即利用水口外的旋转电磁场对钢液的洛伦兹力，使水口内钢液形成旋转流动。对圆形电磁旋流装置作用下圆坯及方坯连铸过程结晶器内钢液流场进行了三维数值模拟，分析了350 A电磁旋流作用下圆坯及方坯结晶器内钢液流场。结果表明：①水口电磁旋流使得圆坯结晶器内的钢液都处于旋转状态。②有旋流时，在方坯结晶器角部的附近可以观察到水平流动；钢液的冲击深度更小，上返流增强。

A New Technology of Swirling Flow in Continuous Casting Process:Electromagnetic Swirling Flow in Immersion Nozzle

The fundamental researches show that, swirling flow in an immersion nozzle can effectively improve the uniformity and stability of the flow from the nozzle, and consequently improve the distribution of flow and temperature, reduce meniscus fluctuation in mold. In this study a new process is proposed, in which a rotating electromagnetic stirrer is set up around an immersion nozzle to induce a swirling flow in it by Lorentz force. The flow distribution in mold for round billet and square billet continuous casting process in a round electromagnetic swirling flow generator with 350A electromagnetic swirling flow is numerically analyzed. The simulation results show that: for round billet, the electromagnetic swirling flow downward from the immersion nozzle can drive all the flow in mold swirling; for square billet, with electromagnetic swirling, a weak swirling flow can be observed at the corner of the meniscus, and the impinging depth of the flow becomes less while the upward flow velocity becomes larger.