2219铝合金环轧过程流变行为及组织演变多尺度数值仿真

Multi-scale simulation of flow behavior and microstructure evolution for AA2219 alloy during multi-pass ring rolling process

开展2219铝合金环轧过程流变行为和显微组织演变的多尺度数值仿真。提出一种与传统热轧成形不同的新环轧技术,包括两阶段的热轧-温轧变形。结果表明,环件截面的温度、应变和应变速率呈现不均匀分布。边部节点大应变使得其内部晶粒被拉长,随着轧制过程的进行,小角度晶界逐渐转变为大角度晶界,使得再结晶百分数提高。固溶处理将轧制变形中拉长的带状组织转变为等轴晶组织,使材料发生完全静态再结晶。不均匀的温度和应变分布使得截面显微组织分布不均匀。通过环轧工艺试验,分析轧制过程中轧制力和环件几何尺寸变化规律。采用提出的新工艺,环件各方向力学性能和各向同性显著提升,尤其是伸长率提升显著。

The multi-scale simulation of flow behavior and microstructure evolution of 2219 aluminum alloy during ring rolling was conducted.A new forming technology with two-stage hot−warm ring rolling was proposed compared to conventional hot rolling.The results show that the distributions of temperature,strain and strain rate are inhomogeneous on the cross section.The grains of edge nodes are elongated resulting from the larger strain and the low-angle grain boundaries transform into high-angle grain boundaries resulting in the increased fraction of recrystallization in hot rolling.The elongated banded structures change to equiaxed grains during the solution treatment,indicating complete static recrystallization.The inhomogeneous distributions of the temperature and strain result in heterogeneous microstructure distribution.The rolling force and the geometry of the ring were analyzed with experiment.The tensile properties in all directions of the ring and its isotropy are significantly increased with the new technology,especially the elongation.