方坯软接触电磁连铸结晶器内钢液弯月面行为的热模拟研究

THERMAL PHYSICAL SIMULATION OF MENISCUS BEHAVIORS OF MOLTEN STEEL IN THE SOFT CONTACT ELECTROMAGNETIC CONTINUOUS CASTING MOLD OF BILLET

以低熔点 Ｐｂ－Ｓｎ－Ｂｉ合金作为钢液模拟工质，对谐波高频磁场作用下，方坯软接触电磁连铸结晶器内钢液的弯月面行为进行热模拟实验研究、通过录像手段记录高频磁场作用下非导电石英玻璃容器内液态金属的弯月面行为，并采用“浸镀法”测得不同实验条件下的弯月面形状，掌握了高频磁场作用下液态金属弯月面的波动特性及不同感应线圈实验参数对弯月面行为特征的影响效果．研究表明：方坯结晶器内高频磁场沿结晶器周向的不均匀分布是影响弯月面稳定性的重要因素，在设计软接触电磁连铸结晶器时，应在结晶器角部对磁场采取适当的屏蔽措施．此外，感应线圈匝数以及感应线圈工作位置的选取将在很大程度上影响到钢液弯月面的形态和稳定性，是影响软接触电磁连铸铸坯表面质量的重要工艺参数．

The thermal physical simulation of meniscus behaviors of molten steel in a EMCC (electromagnetic continuous casting) mold of billet was made. The low-melting-point alloy of PbSn-Bi was used as the simulated media of molten steel, and the harmonic high frequency magnetic field was added for the purpose of soft contacting. The dynamic behavior of the meniscus within the non-conducting silicon glass mold was recorded by pick-up camera and meniscus contours of molten alloy were obtained by immersion plating method. The fluctuating characteristics of meniscus and effects of some factors like the coil turns and coil locations on the meniscus behavior were investigated. The experimental results indicate that the nonuniform distribution of the magnetic flux density around inside walls of EMCC mold is one dominant factor which affects the stabilization of meniscus, therefore the magnetic field at the corner of EMCC mold should be properly shielded, specially for the real design of EMCC mold. Furthermore, in the soft contact EMCC process the turns and location of coil are important to improve the surface quality of cast, because the behavior and stabilization of molten steel meniscus are influenced greatly under these different processing parameters of coil.