(1. 合肥工业大学 材料科学与工程学院，合肥 230009；2. 安徽省电力科学研究院 材料所，合肥 230601)
摘 要: 在自制的微动疲劳试验装置上进行钢芯铝绞导线 (ACSR) 的微动疲劳试验，采用扫描电子显微镜观察分析内、外层铝股线断口特征，研究其微动疲劳断裂机制。结果表明：铝股线的断股大多发生于导线与线夹的最后接触点处。微动振幅为1.0 mm时，在较低循环周次下(1.6×107)，铝股线只发生正断；随着循环次数增加，铝股线断股数量增加，且发生45°及“V”形断裂。铝股线疲劳断口由疲劳源区、疲劳裂纹扩展区、瞬断区构成，呈现弯曲疲劳和扭转疲劳两种不同的断裂方式。
关键字: 钢芯铝绞导线；微动疲劳；疲劳断裂
aluminum conductor steel reinforced overhead conductor
（1. School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009, China;
2. Materials Department, Anhui Electric Power Research Institute, Hefei 230601, China）
Abstract:Fretting fatigue experiment of the aluminum conductor steel reinforced (ACSR) conductor was carried out using a conductor fretting fatigue testing equipment. The fractographies of the external and internal Al strands of the ACSR conductor were analyzed using scanning electron microscope (SEM), and the fracture mechanisms of the Al strands after fretting fatigue were also discussed. The results show that the Al strands mostly rupture at the last contact points of the conductor on the suspension clamp. Under the condition of the fretting amplitude equal to 1.0 mm, only the plane fracture of the Al strands takes place at low fretting cycles of 1.6×107. As the fretting cycles increasing from 1.6×107 to 2.6×107, the number of the broken Al strands increases, and new facture modes, i.e. the 45° and “V”-type fractures, are detected. All fatigue fracture surfaces of the Al strands consist of three regions, e.g. the fatigue source region, the fatigue crack extension region and the instant fracture region, respectively. Two fatigue fracture mechanisms of the Al strands, such as the bending fatigue and the torsional fatigue, are also revealed.
Key words: aluminum conductor steel reinforced conductor; fritting fatigue; fatigue fracture
