Numerical Simulation Study on Temperature Field Optimization of a Vertical Transverse Magnetic Field Heat Treatment Furnace

With the escalating functional requirements of electronic systems in new energy vehicles, the performance specifications for electronic components have become increasingly stringent. Nanocrystalline soft magnetic alloy cores processed via transverse magnetic field heat treatment exhibit exceptional electromagnetic properties, rendering them ideal candidates for electromagnetic interference (EMI) suppression components. However, conventional transverse magnetic field heat treatment furnaces suffer from severe temperature inhomogeneity, which degrades the soft magnetic performance of the cores. In this work, a three-dimensional numerical model of a vertical transverse magnetic field heat treatment furnace is established using SolidWorks 2022, and the temperature distribution is simulated and analyzed using Ansys Workbench 2022 R1. Structural optimizations are then implemented based on simulation results. To validate the simulation model, thermocouples are arranged at multiple points inside the furnace for real-time temperature monitoring, and the measured data are compared with simulation results. Numerical results demonstrate that increasing the number of deflectors of the circulating cooling fan from 8 to 12 reduces the temperature difference within the core working region from 14 ℃ to 11.08 ℃. Further optimization of the heating resistance wire winding configuration — replacing irregular winding with uniform spiral winding at a pitch of 2 mm — lowers the furnace internal temperature difference to 7.59 ℃. Experimental validation using the optimized furnace confirms a substantial improvement in inductance performance, with values increasing by 40%–45% compared with the original furnace. Transmission electron microscopy (TEM) characterization reveals that the average grain sizes of magnetic cores sampled from different furnace positions after optimization are all approximately 18–19 nm, with nearly overlapping grain size distribution curves, confirming the homogenization of the microstructure. Both simulation and experimental results demonstrate that improving furnace temperature uniformity facilitates the formation of uniformly sized nanocrystalline grains, thereby effectively enhancing the inductance performance of the cores. This work provides a reliable engineering solution for achieving stable performance in the mass production of high-performance nanocrystalline cores.