大方坯结晶器内钢液的流动、传热、凝固耦合模拟

aking bloom mold with cross-sectional dimension 240mm×240mm as research object，a three-dimensional mathematical model was established to research effects of the submergence depth of the submerged entry nozzle (SEN) and casting speed on flow field and solidification taking effect of air-gap into account. The simulation result shows that the impact depth in mold with one port SEN is deep which is good for uniform growth of solidified shell. Meanwhile, the air gap has evident effect on corner temperature which is more practical than ignoring air gap. In addition, the distance between backflow vortex core and free surface increases and backflow vortex core moves up obviously, with the increasing of SEN-depth. Solidified shell thickness decreases from 32.43 mm to 17.83 mm with the casting velocity from 0.5 m/min to 0.9 m/min. In conclusion, according to the comparative analysis, the optimal combinations of process parameters are the depth of SEN of 100mm and the casting speed of 0.7 m/min in order to ensure the production efficiency and the bloom quality for the 42CrMo steel with cross-sectional dimension 240 mm×240 mm.