感应熔炼冷坩埚内磁场的分布规律

实验测定了冷坩埚内无负载时空间磁场的分布,考察了输入功率、位置对磁感应强度的影响,计算了无坩埚时空心圆柱线圈内空间磁场的分布,比较了在有无坩埚两种情况下磁场分布特点.结果表明,随着输入功率的逐渐增大,磁感应强度逐渐增大;磁感应强度沿径向分布规律为在坩埚中心位置最小,向坩埚内壁边缘逐渐增大,在坩埚内壁处达到最大;磁感应强度沿轴向分布为中心附近最大,向两端逐渐衰减;坩埚的加入并没有改变空心圆柱线圈内磁场的空间分布规律,还是中间大、两端小,但由于屏蔽作用,大小却有所变化,衰减到线圈内无坩埚时的50%左右,磁场分布趋于平缓.以上实验结果为有效的利用冷坩埚进行感应熔炼提供了实验依据.

Distribution characteristic of magnetic field in cold crucible for induction melting

Experiments were performed using the method of small coil without load to measure the magnetic field distribution in a cold crucible using an induction skull melting(ISM) furnace.It was shown that magnetic induction intensity can be effectively improved by increasing the input power.Along the radial direction inside the cold crucible,magnetic induction intensity was the strongest at the edges and gradually attenuated from the edges to the center.Along the axial direction,magnetic induction intensity was the strongest at the center and gradually attenuated from the center to the edges.The magnetic field was also calculated inside the coil without cold crucible.It was found that the crucible does not influence the distribution of the magnetic field,but due to the crucible's electromagnetic shield effect,magnetic induction intensity reduced about 50% than it should without the crucible.These experimental results provide effectual basis for induction melting in a cold crucible.