Refinement mechanism of low voltage pulsed magnetic field on solidification structure of silicon steel
Refinement mechanism of low voltage pulsed magnetic field on solidification structure of silicon steel
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DOI：
10.1007/s12540-014-3018-1
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发表时间：
2014-05
影响因子：
3.5
通讯作者：
Y. J. Li;Y. Teng;Y. Yang
中科院分区：
文献类型：
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作者：
Y. J. Li;Y. Teng;Y. Yang
采用实验和模拟相结合的方法，研究了低压脉冲磁场（LVPMF）对硅钢凝固组织的细化作用。实验结果表明，采用低压脉冲磁场可以获得完整细小的等轴晶组织。研究了熔体冷却速度和过热度等工艺参数对凝固组织的影响。应用该技术时，在较大的冷却速度或过热度范围内，可以获得完整细小的等轴晶。对凝固过程中的磁场力和熔体流动进行了建模和模拟，以揭示晶粒细化机制。模拟结果表明，LVPMF对合金熔体具有电磁对流和电磁振动的双重作用。提出了细化机制：熔体振动和对流促进形核增殖，促进异质形核，提高形核率，细化晶粒。
The grain refinement of a silicon steel solidified with a low voltage pulsed magnetic field (LVPMF) was investigated by experiments and modeling. The experiment results show that complete fine equiaxed grains are acquired by applying the LVPMF. The effects of process parameters, such as the melt cooling rate and superheating on the solidification structure, were also studied. Complete fine equiaxed grains can be obtained under a larger range of cooling rate or superheating when the LVPMF is applied. The magnetic force and the melt flow during solidification were modeled and simulated to reveal the grain refinement mechanism. The simulation results show that the LVPMF has a double role in electromagnetic convection and electromagnetic vibration on the alloy melt. We propose the refining mechanism: The melt vibration and convection can promote nucleus multiplication, which contributes to heterogeneous nucleation enhancement and leads to a high nucleation rate and grain refinement.