铸态铅黄铜准超塑性拉伸组织变化的研究

采用单向拉伸对铸态铅黄铜进行了准超塑性研究。在温度相同条件下，在较高的拉伸速度下获得了大伸长率。在相同的速度下，随着温度的升高，动态再结晶现象比较明显。金相组织分析表明，在动态再结晶开始时，新的晶粒首先出现在晶界附近。随着变形量的增加，再结晶区由晶界逐渐向晶粒内部扩展，最后动态再结晶完成，整个晶粒内部完全细化。

Study of Microstructural Evolution of As-cast Lead Brass During Elongation of Quasi-Superplasticity

The quasi-superplasticity of as-cast lead brass was studied by monodirectional elongation experiment. At the same temperature, the as-cast lead brass has the finer prolongation at the higher velocity. At the same velocity, the dynamic recrystaUization phenomenon is rather distinct with the rise of temperature.The analysis on metallographic structure indicates that the new crystal firstly appears nearby crystal boundary at the beginning Of the dynamic recrystaUization;the recrystallization area expands from crystal boundary to crystal interior with the increase of deformation. When the dynamic recrystallization completing, the whole crystal becomes small and thin.