The distribution of microstructure (such as subgrain size) in the cross section of the extrudate is non - umiform under the normal extrusion conditions in which the ram velocity is constant.

• 常规挤压条件下(推杆速度不变),热挤压件的微观组织(例如亚晶粒)沿长度方向的分布是不均匀的。