镍基高温合金电子束焊接接头疲劳性能
Fatigue properties of electron beam welded joints of Nickelbase superalloy
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摘要: 对GH4169高温合金板材电子束焊接试样进行了金相分析和高、低周疲劳试验,分析GH4169合金的高、低周疲劳性能及疲劳断口形貌.结果表明,GH4169合金电子束焊接接头焊缝区的特点是树枝晶比较明显,为比较发达的树枝晶和明显的二次枝晶.在较高放大倍数下发现,母材和热影响区也为树枝晶结构.接头低周疲劳性能不低于母材,随应变幅降低,相同应变幅下焊接接头疲劳寿命变得略高于母材.接头高周中值疲劳强度比母材高约80 MPa.Abstract: The microstructure,high and low cycle fatigue properties of GH4169 electron beam (EB) welded joints were investigated. The results show that the EB weld of GH4169 alloy consisted of dendrite structures with the developed dendrite and secondary dendrite. The heat-affected zone (HAZ) and base metal showed also dendrite structure. The low cycle fatigue properties of joints were not lower than those of the base metal. With strain amplitude reduced,the low cycle fatigue life of joints became higher than that of the base metal at the same strain amplitude. The median high cycle fatigue strength of joints was about 80 MPa higher than that of the base metal.