基于界面追踪-动网格技术模拟凝固收缩下Fe-C合金宏观偏析

董士虎, 张红伟, 吕文朋, 雷洪, 王强

Numerical Simulation on Macrosegregation in Fe-C Alloy Under Solidification Shrinkage Through Interface Tracking-Dynamic Mesh Technique

DONG Shihu, ZHANG Hongwei, LÜ Wenpeng, LEI Hong, WANG Qiang

表1 模拟合金的物性参数[18,30,31]

Table 1 Thermodynamic and physical parameters of modelling alloys[18,30,31]

Parameter Unit Sn-5%Pb alloy* Fe-0.3%C alloy Ref. Melting point of pure solvent Tf K 505.15 1805.15 [30] Liquidus slope m K·%-1 -1.286 -80.45 [30] Equilibrium partition coefficient k - 0.0656 0.36 [30] External temperature K 298.15 300 [30] Melt density ρl kg·m-3 7000 7027 [18] Solid density ρs kg·m-3 7000 7324 [18] Specific heat cp J·kg-1·K-1 260 500 [30] Thermal conductivity ks W·m-1·K-1 55 34 [30] Latent heat L J·kg-1 6.1 × 103 2.71 × 105 [30] Viscosity μ kg·m-1·s-1 1 × 10-3 4.2 × 10-3 [18] Thermal expansion coefficient βT K-1 6 × 10-5 1.07 × 10-4 [30] Solutal expansion coefficient βc %-1 -5.3 × 10-4 1.4 × 10-2 [30] Secondary dendrite arm spacing λ2 m 6.5 × 10-5 5 × 10-4 [30] Diffusion coefficient of C in liquid Dl m2·s-1 1 × 10-8 2 × 10-8 [18] Reference temperature Tref K 499.15 1782 Reference concentration (mass fraction) cref % 5 0.3 Reference temperature in enthalpy definition T0 K 273 273 Time step Δt s 0.1 0.05