转速对FGH96/GH4169高温合金惯性摩擦焊接头组织与力学性能的影响

Effect of rotation speed on microstructures and mechanical properties of initia friction welded joint of FGH96/GH4169 dissimilar superalloys

应用惯性摩擦焊机完成了FGH96/GH4169高温合金焊接,采用光学显微镜、扫描电镜以及拉伸试验机等设备观察并测试了焊接接头的微观组织形貌、显微硬度及拉伸性能。结果表明接头存在FGH96侧母材、热力影响区、焊缝区、GH4169侧热力影响区及母材五个区域,焊缝区组织为细小的等轴晶粒,晶粒尺寸远小于母材,热力影响区则发生了拉伸变形。接头近界面处最高温度达到1 100℃以上,超过γ'等强化相的固溶温度。焊后热力影响区处强化相部分重溶,在界面细晶区强化相几乎完全重溶。随着转速增大,焊缝区晶粒增大,典型原子的扩散距离增加,接头室温抗拉强度和高温抗拉强度值升高。

The joint of FGH96/GH4169 dissimilar superalloys was obtained by changing rotation rate on Inertia Friction Welding machine and the welded joint temperature was measured.After welding,optical microscope,Scanning Electron Microscope(SEM)and tensile testing machine were used to investigate the microstructures and mechanical properties of the joint.The results showed that the temperature around the interface nearly exceeds 1 100℃.The microstructure in the weld zone(WZ)consists of refined and equiaxed grains and that in the thermos-mechanically affected zone(TMAZ)consists of deformed grains.After weddingγ’andγ"partly soluted in TMAZ and practically in WZ.The sizes of the refined grains become larger with rotation rate being increased.Elemental diffusion exists on the interface and the diffusion become wider with the increased rotation rate.The results of tensile properties show that the tensile strength rises with the rotation rate.