开坯轧机大压下量对大棒材芯部的影响

Effect of Huge Forming on Big Bar Core in Break-down Mill

基于有限元仿真对比分析了大棒材在开坯轧制前两道次中不同变形程度对轧件芯部的影响。仿真结果表明:两道次压下量在90mm和70mm时的轧件等效应力比两道次压下量都在65mm时大200MPa;轧件等效应力随道次增加而增加,变形程度增加使得轧件轧后残余应力增加;等效塑性应变随着道次变形程度增加而增大,而大的变形程度会促使等效应变渗透至轧件芯部,为消除或减小轧件芯部组织缺陷提供解决措施,从而提高材料的使用寿命。

The influence of different deformation degrees on big bar core in two passes before breaking down was analyzed based on FE simulation. The simulation results show that the effective stress of rolling blank when two passes rolling reduction at 90mm and 70mm is larger 200MPa than two passes rolling reduction at 65mm and 65mm; the effective stress of rolling blank increases with increasing passes,and the increase of the deformation degree brings the residual increasing stress; the effective plastic strain increases with the increase of the deformation degree, but the large deformation degree may make effective strain permeate to the core of bar. This can provide solving measure for eliminating or decreasing core microstructure defect to increase the material service life.