(1. 合肥工業(yè)大學 材料科學與工程學院，合肥 230009；2. 安徽省電力科學研究院 材料所，合肥 230601)
摘 要: 在自制的微動疲勞試驗裝置上進行鋼芯鋁絞導線 (ACSR) 的微動疲勞試驗，采用掃描電子顯微鏡觀察分析內(nèi)、外層鋁股線斷口特征，研究其微動疲勞斷裂機制。結果表明：鋁股線的斷股大多發(fā)生于導線與線夾的最后接觸點處。微動振幅為1.0 mm時，在較低循環(huán)周次下(1.6×107)，鋁股線只發(fā)生正斷；隨著循環(huán)次數(shù)增加，鋁股線斷股數(shù)量增加，且發(fā)生45°及“V”形斷裂。鋁股線疲勞斷口由疲勞源區(qū)、疲勞裂紋擴展區(qū)、瞬斷區(qū)構成，呈現(xiàn)彎曲疲勞和扭轉疲勞兩種不同的斷裂方式。
關鍵字: 鋼芯鋁絞導線；微動疲勞；疲勞斷裂
aluminum conductor steel reinforced overhead conductor
ZHANG Tao2, XU Guang-qing1, TANG Wen-ming1
（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
