电渣重熔过程中的电磁场和Joule热分析

来源期刊：金属学报2010年第7期

论文作者：王芳 李宝宽

文章页码：794 - 799

关键词：电渣重熔； 电磁场； Joule热； 数值模拟

Key words：electroslag remelting processes； electromagnetic field； Joule heating； numerical simulation

摘    要：以电渣重熔工艺中电极、渣池和钢锭为研究对象,建立了能够考虑集肤效应的三维谐波电磁场有限元模型,采用Maxwell方程、Lorentz定律和Joule定律分析了渣、钢锭和电极的磁场、电磁力、电流密度和Joule热功率密度的分布.模拟结果与测量的电渣重熔系统外部空气的磁感应强度吻合良好,证明了本模型和计算过程的可靠性.计算结果表明:在电极和钢锭内,电流主要集中在外表面,电流沿轴向方向;在渣池内,由于渣的电导率低,电流分布发生改变,主要集中在电极端头处;电磁力的最大值出现在接近渣池上表面渣内的电极附近;而Joule热的最大值是在电极底部与渣的交界处;当频率大于35 Hz时,电极和钢锭内都出现了涡流;当电极浸入深度增大或渣层的厚度减小时,渣池中Joule热的最大值增大.

Abstract: A 3D finite element model was developed to simulate the magnetic field,electromagnetic force,current density and Joule heating of electroslag remelting processes (electrode,slag and ingot) by using of Maxwell equation,Lorentz law and Joule law.Especially,the skin effect is shown and discussed based on numerical results.The results show that the current distribute on the external surfaces of slag and ingot.In slag,due to the low electrical conductivity of slag,the current distribution changes,gathering on the end of electrode.The maximum electromagnetic force is at the upper surface nearby the electrode and the maximum joule heating is at the interface of electrode and slag.When current frequency is greater than 35 Hz,the vortex flow will occur in interior of electrode and ingot. When electrode immersion depth increase and slag cap thickness decrease,the maximum of the joule heat in slag will increase.