用改进的有限元模型分析二辊斜轧穿孔过程

Analyse piercing in two-roll rotary rolling process with FE modeling

借助有限元软件MSC. SuperForm2005,建立了新型的2D模型。采用Oyane断裂准则对圆坯二辊斜轧时的内撕裂形成过程进行二维热-力耦合数值模拟。模型中不仅反映了轧辊送进角和轧辊入口锥角的影响,而且还考虑了辊径的影响。结合宝钢140 mm全浮芯棒连轧机组Diescher穿孔机的工具和变形参数,分析了管坯斜轧时的应力应变状态和韧性断裂的特征值的分布状况,得到了管坯临界压下率。数值模拟结果与实际吻合较好,从而对生产过程合理确定变形参数有指导意义。

With the aid of FE code MSC. Superform 2005, 2-D coupled thermo - mechanical simulation of center - crack occurrence in round billet in 2-roll rotary rolling process is presented using Oyane ductile fracture criteria. An improved FE model is advanced, in which not only the influence of feed angle and entry cone angle but also the diameter of the main roll in the process are taken into account. By adopting the parameters of Diescher piercer in 140mm Mandrel Mill of Bao Steel, the distribution and development of strain/stress in tube rounds are analyzed, and the eigenvalue of ductile fracture as well. The critical percentage of diameter reduction is obtained from the simulation. The result shows a good agreement with the experimental value, and, therefore, is of widely guiding significance to practical process for rationally formulating deformation parameters of steel tube piercing.