坯料形状对大棒材开坯轧制变形的影响

为研究圆坯和矩形坯两种坯料形状对大棒材开坯轧制变形的影响,采用有限元分析软件MARC对大棒材开坯轧制进行了模拟。模拟结果表明:在箱型孔中开坯轧制时,轧件芯部附近变形区应力状态都是两拉一压,矩形坯残余应力呈两拉一压应力状态而圆坯是三向拉应力状态;矩形坯比圆坯在箱型孔中的充满度好,等效应变分布均匀;当孔型侧壁起限制宽展作用时,轧件芯部呈现两压一拉应力状态,变形向芯部渗透明显,利于芯部孔隙性缺陷的压实。

Effect of billet shape on rolling deformation of large gauge bar

In order to study the influences of round billet and rectangular billet on the rolling deformation of large gauge bar,FEM software MARC was used to simulate the hot rolling process.The simulation results indicate that when conducting break-down rolling in box pass,the stress state of rolled piece in deformation zone is two tensile stresses and one compressive stress.And the residual stress of rectangular billet is two tensile stresses and one compressive stress,while the residual stress of round billet is three tensile stresses.When the spread is restricted by the slope of side wall,the stress state is two compressive stresses and one tensile stress,and deformation significantly penetrates into the core which will help compact core porosity defects.