耐张线夹内钢芯铝绞线断裂原因及断口特征  

Fracture Causes and Characteristics of Aluminum Cable Reinforced Conductor Steel in Strain Clamp

作　　者：王伟[1] 朱成丽[2] 吴洪亮[2] 李晓红[2] 

机构地区：[1]广东电网公司电力科学研究院,广州510080 [2]武汉大学动力与机械学院,武汉430072

出　　处：《腐蚀与防护》2014年第3期297-301,共5页Corrosion & Protection

基　　金：广东电网公司科技项目(K-GD2012-386)

摘　　要：针对一起运行18a的耐张线夹处导线失效事故,采用宏观检查、扫描电镜、力学性能测试及金相组织检验等分析手段,由失效线夹特征及绞线断口形貌、组织性能劣化特点研究了其失效原因和机理。结果表明,耐张线夹铝管一侧压痕明显,另一侧积垢;外层铝股表面有大量腐蚀坑;铝股及钢芯的断面收缩率增加10%以上;铝股、钢芯断口纵向金相纤维特征弱化,钢芯断口颈缩处纤维特征消失。该次断线主要是线夹压接不良致管内钢芯铝绞线与线夹接触面腐蚀,灰尘、腐蚀产物在管内结垢,发热量增加,绞线温升,材质劣化而引起的。To reveal the failure causes and mechanism of the conductor serviced for 18 year in the strain clamp, macroscopic examination, scanning electron microscopy, spectroscopy analysis, mechanical testing and metallographic examination were applied to analyze the characteristics of failed clamp and the fracture morphology and microstructure degradation characteristics of the conductor. It was found that half of the inner wall of strain clamp was seriously compressed, while the other half was covered by thick scaling layer. There were a lot of corrosion pits on the surface of outer layer aluminum strands. The area reductions of aluminum strands and steel cores had an increase of 10%. The fibrous characteristics of the longitudinal metallographic structure weakened at the fractures of failed aluminum strands and steel cores, and even disappeared at the necking of steel cores. The poor compression in the clamp caused the corrosion in the contact surface of the conductor and the clamp, leading to the scaling of corrosion products and dust and the increase of heat produced in the tube. The failure finally occured due to the temperature elevation and material deterioration.

关 键 词：耐张线夹 断线 压接不良 蚀坑 材质劣化 

分 类 号：TG174[金属学及工艺—金属表面处理]