Zr-4合金板材冷轧过程材料变形晶体塑性分析与织构演变

Deformation analysis of crystal plasticity and texture prediction of Zr-4 alloy during cold rolling process

摘要:

选取厚度为3.6mm具有典型双峰织构的Zr-4合金板材，利用电子背散射衍射（EBSD）技术对板材冷轧后的织构进行表征，利用粘塑性自洽（VPSC）模型对板材冷轧后的变形机理进行分析。VPSC模型预测了轧制道次数量、每道次压下量以及总变形量对冷轧织构以及变形机理的影响规律，结果表明Zr-4合金板材在冷轧后，织构保持典型的基面双峰织构；轧制道次数、单道次压下量对冷轧后的织构以及变形机理无明显影响；总变形量对冷轧后的织构有明显影响，随着轧制总变形量减小，大部分晶粒的c轴由法向（ND）向宽向（TD）转动；当变形量低于临近变形量39%时，法向科恩系数（Fn）随着变形量的增大而快速增大，柱面滑移开启快速降低，当变形量超过39%时，法向科恩系数（Fn）的增长趋于平缓，柱面滑移的开启趋于稳定。

Abstract:

A cold rolled Zr-4 alloy sheet of 3.6mm thickness with a typical bimodal texture was applied. Texture evolution was characterized by electron backscattering diffraction (EBSD) technique. Visco-plastic self-consistent (VPSC) model was analyzed to evaluate deformation mechanism of Zr-4 alloy sheet during cold rolling. Effects of rolling pass number, reduction per pass and total deformation on texture were predicted with the VPSC model. Results show that the texture of Zr-4 alloy sheet maintained a typical basal bimodal texture during the cold rolling process. Rolling pass number and reduction per pass had little influence on the texture evolution and deformation mechanism. However, total rolling deformation had significant effect on the texture evolution. With the decrease of deformation, the C-axis of most grains rotated from the normal direction to the transverse direction; When the rolling deformation is less than the critical deformation which is 39%, the Kearn factors of normal direction (Fn) rises rapidly with the increased deformation, and prismatic slip quickly decreases.When the deformation exceeds 39%, only slight increase of Kearns factor was observed, and prismatic slip becomes stable.