电磁制动下板坯连铸结晶器内金属流场三维模拟的基本流态与主流场分析

在物理模拟实验的基础上, 采用基于标准k-ε 湍流模型的三维稳态流动与磁场耦合模型, 对电磁制动(electromagnetic braking, EMBr)条件下板坯连铸结晶器中的金属流场进行数值模拟, 研究了磁场强度及其分布对结晶器内金属流动的影响, 并与物理模拟结果进行了对比, 进一步揭示了在物理模拟中受传感器数量等限制所无法观察到的一些细微现象或局部流态及流动行为. 结果表明, 在流动控制结晶器(flow control mold, FC Mold) 电磁制动方式下,结晶器内流场具有复杂的三维特性. 此时必须注意结晶器液面流速过慢所导致的表面夹杂、横裂等问题. 合适、有效的电磁制动也应与连铸工艺相匹配.

Analysis of liquid metal flow with electromagnetic braking in continuous casting of slab by three-dimensional simulation

Using mercury as working medium in the earlier study, physical simulation was intended to investigate the liquid flow in a mold of slab in continuous casting with electromagnetic braking (EMBr). From the restrictions on the size and quantity of the sensors, the result of mercury model was limited to analysis in a two-dimensional flow field. Based on the previous physical simulation, a three-dimensional flow was simulated numerically with a standard k-ε turbulence model to investigate influences of the magnetic field intensity, and distribution on the metal flow in the mold of slab in continuous casting with and without EMBr. Simulation results were compared with the physical results. It was found that the simulation could reveal more detailed phenomena and flow behaviors. These could not be observed in physical simulation as restricted by the quantity of sensors. The results indicated that a flow field in a crystallizer had a complex three-dimensional flow field characteristic with a flow control mold (FC Mold) EMBr mode. More attention must be paid to mold slow liquid level caused by surface inclusions, transverse crack and other factors. Appropriate and effective EMBr should match the continuous casting process.