The microscopic heat transfer mechanism of metallurgical materials has a significant impact on the material properties, and the traditional numerical methods are difficult to deal with complex boundary conditions and multi-scale heat transfer problems. In this paper, the lattice Boltzmann method (LBM) is adopted to study the microscopic heat transfer mechanism of metallurgical materials, and a large-vortex simulation framework based on the D3Q19 model is established, and the coupling of the phase field method and the lattice Boltzmann method (PFLBM) is realized. The study simplifies the Boltzmann equation through the BGK collision operator, introduces the Smagorinsky sublattice model to deal with turbulence, and employs the bounce format and the nonequilibrium extrapolation format to deal with boundary conditions. The flow field, temperature field, solute field and phase field are coupled to realize the multi-field coupled simulation in micro-macroscopic scale. The results show that in the simulation of heat transfer power loss of the torque converter, the simulated value of 15.62 kW agrees well with the experimental value of 16.82 kW when the rotational speed is 1600 r/min; in the simulation of discontinuous heat transfer in nanoscale, the D2Q37 lattice model effectively overcomes the internal unphysical temperature jump effect and the boundary accuracy is improved by 27% when Kn = 0.42. The conclusion confirms that the method can accurately simulate the heat transfer process of metallurgical materials at different scales, which provides a theoretical basis for optimizing the thermal properties of materials.
