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以低熔点Sn-32%Pb-52%Bi合金作为模拟介质,实验研究了高频交变磁场以及复合磁场(交变磁场+静磁场)作用下结晶器内液面波动及其不稳定行为.实验发现,单独施加交变电磁场时,液态金属表面处于波动状态,随着交变磁场磁感应强度增加,液面会依次出现稳定凸起圆台形变形和液柱的随机摆动现象;发生摆动时的凸起液面主要呈柱状和三棱柱状,此时液面中心波动略强于三相点处.随交变磁场磁感应强度增加,中心点处的波动主频率逐渐增大.横向水平静磁场(0—1.44 T)的施加能显著抑制交变磁场作用下变形液柱的不稳定摆动行为;增加静磁场磁感应强度,液柱的摆动幅度减弱.静磁场可以有效抑制液面的波动,增加静磁场强度,熔池自由表面出现拉伸现象,在强静磁场作用下,液面出现规则层波.实际应用中应有一个合理的静磁场磁感应强度范围,此时液面较稳定,液面波动振幅和主频率均较小.
Using the low melting point Sn-32% Pb-52% Bi alloy as the simulation medium, the fluctuation of the liquid surface and its instability in the mold under high-frequency alternating magnetic field and composite magnetic field (alternating magnetic field + static magnetic field) were studied experimentally. The experimental results show that when the alternating electromagnetic field is applied alone, the surface of the liquid metal is in a fluctuating state, and as the magnetic induction of the alternating magnetic field increases, The liquid level is mainly columnar and triangular prism, and the center of the liquid level fluctuates slightly stronger than the three-phase point. With the increase of the magnetic induction intensity of the alternating magnetic field, the main frequency of fluctuation at the center point gradually increases. -1.44 T) can significantly inhibit the unsteady oscillating behavior of the deformed liquid column under the action of alternating magnetic field, increase the magnetic flux density of the static magnetic field, and decrease the swing amplitude of the liquid column. The static magnetic field can effectively suppress the fluctuation of the liquid surface and increase the static magnetic field intensity , The molten pool free surface tensile phenomenon, under the action of strong static magnetic field, the surface layer of the wave of the rule of law there should be a reasonable magnetic field strength range of static magnetic field, the liquid surface is more stable, Small and frequency rates.