TA2钛合金焊接接头不同区域的疲劳裂纹扩展速率

Fatigue Crack Propagation Rates in Different Zones of TA2 Titanium Alloy Welded Joint

对TA2钛合金焊接接头的母材区、熔合线、焊缝中心和热影响区的疲劳裂纹扩展速率、疲劳断口形貌以及显微组织进行了研究。结果表明:接头各区域的疲劳裂纹扩展速率相差不大,可直接用焊缝区的裂纹扩展速率表示;各区域试样的断口呈典型的疲劳断口形貌;母材区的平均晶粒尺寸约62.8μm,热影响区的约为110μm,晶粒尺寸对疲劳裂纹扩展速率没有明显影响。

The fatigue crack propagation rate,fatigue fracture morphology and microstructure in base metal,fusion line,weld center and heat affected zone of TA2 titanium alloy welded joint were studied.The results show that the fatigue crack propagation rates in different zones of the joint had small difference and thus could be directly presented by the crack propagation rate of the weld zone.The fracture of samples from different zones illustrated typical fatigue fracture morphology.The average grain size of the base metal was about 62.8μm,and that of the heat affected zone was about 110μm.The grain size had little influence on the fatigue crack propagation rate.