棒材热轧过程的三维温度场有限元分析

Three-dimensional elastic-plastic finite element analysis of bar hot rolling process

基于有限元分析软件MARC,采用更新的Lagrange法描述的热力耦合大变形弹塑性有限元模型和四面体等参单元技术,考虑接触界面传热,对棒材热轧成形工序进行了三维温度场模拟。模拟结果表明:在轧件开始咬入与轧辊接触后,轧件表面的温度与应力急剧上升;由于接触摩擦与塑性变形功转化为热量,轧件在开始轧制时表面温度升高,进入粘着区后,由于摩擦消失,轧件表面温度略有下降,进入后滑区后,先略有回升接着平缓下降;由表及里,轧件的温度逐步降低。

Based on the MARC, the 3-dimensional thermo-mechanical couple elastic-plastic finite elements simulation for the finished stand of bar hot rolling process was accomplished with renewed Lagrange. The material rheological model related to temperature, strain and strain rate was adopted, and the contact heat transfer condition was considered. The three-dimensional thermo-field analysis of round bar hot rolling process was accomplished. An equivalent heat method was proposed to analyse the temperature and stress fields of assembled roller. The results show that the temperature and stress at the surface of the bar increase rapidly at the beginning of contact occurring between the bar and rollers. The increase of the temperature of bar at the beginning of rolling is due to the heat transformed from the friction and plastic deformation work, and at stick zone, the surface temperature of bar decreases slightly because the friction vanishes at the stick zone, and then at the back slip zone, the temperature increases slightly and then decreases gently.