通过高周疲劳性能测试和组织形貌观察,研究了K416B镍基高温合金700℃的高周疲劳行为.结果表明,在700℃和应力比R=-1条件下,合金疲劳寿命随着应力的升高而减小,高周疲劳强度为175 MPa;在低应力条件下,形变位错在γ基体中发生不同取向滑移,随着应力增加,位错剪切γ’相,形成层错;在拉压高周疲劳期间,合金中开动多个滑移系,并沿不同方向发生扭曲变形,在γ+γ’共晶及碳化物附近产生应力集中,致使裂纹源萌生于合金表面附近的共晶及块状碳化物处.随着高周疲劳进行,裂纹在扩展区沿枝晶间扩展,并在瞬断区发生典型的解理断裂. The high-cycle fatigue behavior of K416B nickel-base superalloy at 700 ℃ was studied by high-cycle fatigue test and microstructure observation.The results show that the fatigue life of alloy K416B increases with the stress at 700 ℃ and the stress ratio R = -1 And the high cycle fatigue strength is 175 MPa. Under low stress conditions, the deformation dislocations undergo different orientation slip in the γ matrix, and as the stress increases, the γ ’ During the high-tension and high-tension fatigue, many slip systems were activated in the alloy and distorted in different directions, resulting in stress concentration near the γ + γ ’eutectic and carbide, which caused the source of cracks to originate in the vicinity of the alloy surface Crystal and massive carbides.With the high-cycle fatigue, the crack propagates along the dendrite in the extended zone and a typical cleavage fracture occurs in the instantaneous zone.