挤压工艺参数对Gr.38钛合金管材组织和性能的影响

Effects of Extrusion Parameters on Microstructure and Properties of Gr.38 Titanium Alloy Pipe

通过选择不同的挤压温度、挤压比和挤压速度,研究了挤压温度、挤压比和挤压速度对Gr.38钛合金管材组织和性能的影响。结果表明,当挤压温度、挤压比或挤压速度提高时,α相的含量降低,初生α相再结晶更充分,从扭曲拉长的形态逐步转变为球状,同时合金的强度均略微下降,塑性则略微上升。这是因为合金内部聚集的变形热和变形储能越来越多,发生了动态回复和再结晶。获得了Gr.38钛合金的优化挤压工艺参数:挤压温度为900~930℃,挤压比为14~18,挤压速度为70~80mm/s。

By adopting four extrusion temperature,three extrusion ratio and three extrusion speed,effects of extrusion temperature and extrusion ratio as well as extrusion speed on the properties and microstructure of Gr.38 titanium alloy were investigated.The results reveal that the extrusion parameters have significant influence on the microstructure of Gr.38（ATI425）titanium alloy.With increasing in the extrusion temperature and extrusion ratio as well as extrusion speed,volume fraction ofαphase is decreased,and primaryαphase is recrystallized more fully,which is transformed from the distorted elongated shape gradually into spherical ones.Meanwhile,strength of the alloy is declined slightly with slightly rising of the elongation,which is attributed to more and more deformation thermal and deformation energy stored in the alloy resulting in the dynamic recovery and recrystallization.The optimized extrusion parameters of Gr.38 titanium alloy are presented as follows：extrusion temperature of 900～930℃,extrusion ratio of 14～18and extrusion speed of 70～80mm/s.