(天津大学 材料科学与工程学院，天津 300350)
摘 要: 重点研究在给定的不同高温条件下，GH4169电子束焊焊接接头所表现出的高温稳定性。采用金相、SEM和拉伸等实验对经过不同高温氧化时间的试样进行显微组织观察和力学性能分析。结果表明：GH4169电子束焊缝中心区为树枝晶和胞状树枝晶，由于高温氧化时间和第二相颗粒钉扎作用的相互影响，晶粒随着高温氧化不断长大，直到25 h时，晶粒尺寸达到极大值；随后晶粒大小有减小的趋势，在50 h以后，晶粒继续变得粗大。焊接接头在650 ℃的高温氧化下，25 h时机械拉伸性能达到最佳，在75 h时接头的机械拉伸性能低于常温接头的性能；焊接接头经过长时间的高温氧化，表面会生成较致密的氧化膜。
关键字: 高温合金GH4169；电子束焊；高温稳定性
（School of Materials Science and Engineering, Tianjin University, Tianjin 300350, China）
Abstract:The stability of GH4169 electron beam welding joints was studied under different high temperature conditions, and its high temperature stability performance under corresponding time conditions was explored. The microstructure and mechanical properties of the samples after different high temperature corrosion time were studied by optical microscope, SEM and tensile test. The results show that the center region of the weld of GH4169 alloy is dendritic and cellular dendritic. Due to the interaction between the high temperature corrosion time and the pinning effect of the second phase particles, the grains grow continuously with high temperature corrosion, reaching a maximum value at 25 h, and then the grain size has a tendency to decrease, and the grains continue to become coarse after 50 h. Under high temperature corrosion at 650 ℃, the mechanical tensile properties of the welded joints reach the best at 25 h, and the mechanical tensile properties of the joints at 75 h are lower than those of the joints without high temperature corrosion. A layer of dense oxide film will be formed on the surface of welded joint after a long time high temperature corrosion.
Key words: GH4169 superalloy; electron beam welding; high temperature stability
