局部热处理对TC4钛合金电子束焊接组织性能的影响

Effect of local heat treatment on microstructure and properties of TC4 titanium alloy by electron beam welding

采用柔性加热器对TC4钛合金电子束焊接试样进行局部退火热处理,研究并揭示了焊接试样退火热处理后的组织和性能变化规律。结果表明,焊接试样经过局部退火热处理后,焊接试样的显微组织没有发生明显的变化。焊接态试样和局部热处理试样的显微硬度从焊缝区到热影响区再到基材区,显微硬度逐渐减小,局部热处理试样焊缝区的显微硬度比焊接态试样焊缝区的显微硬度大9 HV0.2,局部热处理试样热影响区的显微硬度比焊接态试样热影响区的显微硬度大14 HV0.2。局部热处理试样的抗拉强度为978.67 MPa,屈服强度为917.67 MPa,断后伸长率为13.97%。局部热处理试样比TC4钛合金锻件的抗拉强度大22.67 MPa,屈服强度大16.67 MPa,断后伸长率小1.43%。

Electron beam welding(EBW)samples of TC4 titanium alloy were annealed by flexible heater.The microstructure and properties of the samples after heat treatment were studied.The results showed that the microstructure of the samples had no obvious change after local annealing heat treatment.The microhardness at the weld seam of the heat-treated samples was 9 HV0.2 higher than that of the untreated samples,and the microhardness in the heat affected zone of the heat-treated samples was 14 HV0.2 higher than that of the untreated samples.The tensile strength and yield strength of the heat-treated samples were 978.67 MPa and 917.67 MPa respectively,and the elongation after fracture was 13.97%.Compared with TC4 titanium alloy forging,the tensile strength and yield strength of the heat-treated samples increased by 22.67 MPa and 16.67 MPa respectively,and the elongation after fracture decreased by 1.43%.