宽厚板坯连铸结晶器流场、温度场及应力场的耦合数值模拟

利用ProCAST软件对2400 mm×400 mm宽厚板坯结晶器建立三维动态模型，采用移动边界法实现结晶器内流场、温度场及应力场的耦合模拟.结果表明：考虑凝固坯壳的影响，下回流区位置向铸坯中心靠拢，真实反映了钢液在连铸结晶器内的流动情况.自由液面的钢液从窄面流向水口，速度先增大后减小，距水口约0.7 m处，出现最大表面流速，约为0.21 m· s-1.结晶器出口坯壳窄面中心厚度最小且由中心向两侧逐渐增大，最小厚度约为10.4 mm；受流股冲击影响较弱的宽面坯壳与窄面相比生长更均匀，宽面偏角部和中心的坯壳厚度分别为18.9 mm和27.6 mm.铸坯坯壳应力变化趋势与温度基本保持一致，表明初凝坯壳应力主要是热应力.结晶器内铸坯宽窄面上的等效应力均沿着结晶器高度下降方向呈增大趋势，铸坯角部、宽面中心及窄面中心位置的最大应力各约为200、100和25 MPa.

Coupling numerical simulation of flow field,temperature field and stress field in a wide-thick slab continuous casting mold

Based on a moving boundary approach, a three-dimensional dynamic model is built for 2400 mmí400 mm wide-thick slab molds by using ProCAST to realize the coupling simulation of flow field, temperature field and stress field. The results show that the position of the lower recirculation zone moves to the slab center by the effect of the solidified shell, which reflects the real flow condition of molten steel in the continuous casting mold. The liquid on the free surface flows from the narrow surface to the nozzle, the velocity increases first and then decreases, and the maximum velocity is about 0. 21 m·s-1 , which occurs at 0. 7 m from the nozzle. The center of the narrow face shell at the mold exit is the thinnest and increases from the center to both sides gradually, and the mini-mum thickness is about 10. 4 mm. The wide face shell influenced by water flow impact grows more uniform than the narrow face, the wide face shell thickness near the corner is 18. 9 mm, and the center thickness is 27. 6 mm. The stress change trend of the slab shell is almost consistent with temperature, demonstrating that the initial solidified shell stress is mainly thermal stress. The effective stres-ses on the wide face and narrow face rise along the drop direction of mold height, and the maximum stresses of the slab corner, wide face center and narrow face center are about 200, 100 and 25 MPa, respectively.