TA15钛合金多道次等温局部常规锻热变形行为研究

Study on Hot Deformation Behavior of TA15 Titanium alloys During Multi-step Conventional Isothermal Local Forging

通过热模拟压缩试验研究了TA15钛合金多道次等温局部常规锻条件下材料的变形及微观组织演化行为,结果表明:多道次局部锻时每个加载道次下,先后加载区的真应力-真应变曲线表现为典型的动态再结晶曲线类型,但流变应力随加载道次的增加而降低,相应道次下先加载区的流变应力大于后加载区;通过多道次局部锻可获得与单道次整体锻造相似的等轴组织,但微观组织晶粒度略大;多道次局部锻先、后加载区微观组织无太大差异,可满足大型构件整体成形对微观组织一致性的要求。

The hot deformation behavior and microstructure evolution of TA15 titanium alloy during multi-step conventional isothermal local forging was studied by isothermal compression.The results indicate that during multi-step local forging,the true stress-true strain curves of both first and second forging regions obtained from each step show a typical character of dynamic recrystallization.But the flow stress reduces with loading times increasing.Besides,in each step,the flow stress of the first loading region is lower than the second loading region.The microstructure obtained from the multi-step local forging is equiaxed structure,which is similar with the microstructure obtained from single pass integral forging,but the phase size is little larger.Both the microstructure of first and second forging regions are almost the same,which can meet the requirement of microstructure-identical of large-scale component.