电场作用下钢芯铝绞线微动腐蚀损伤机理研究

Aluminium conductor steel reinforced(ACSR) is being widely adopted in HV transmission line. ACSR has multiple failure modes mainly in fretting corrosion under wind induced vibration and atmospheric corrosion during service term. We found from the records of power infrastructure maintenance and our primary study that metal structure suffer more serious corrosion in atmospheric environment due to the electric field generated from power lines. The effect of electric field on corrosion is bound to affect the fretting corrosion process. In this project, the fretting damage of ACSR under electric field and atmospheric corrosion will be studied and the fretting corrosion process will be investigated in detail..In this project, mechanical conditions and the characterization of atmosphere and electric field in power industry will be analyzed, and research system will be built up. The effect of electric field on the fretting corrosion process of ACSR will be studied by using electrochemical measurement, surface analysis and structure analysis. Fretting damage process will be investigated by analyzing the fretting corrosion products, fretting wear surface and the characterizations of fatigue cracks initiation, crack propagation and fracture zones. The fretting damage mechanisms of ACSR under electric field and atmospheric corrosion coupling effect will be achieved through macroscopic-microscopic experimental investigations. The results can provide supports of theory and methods for deepening understanding this damage mode and maintenance of transmission line.

钢芯铝绞线(ACSR)广泛应用于高压输电线路。服役中的ACSR导线在风致振动和大气腐蚀环境下会产生以微动腐蚀为主的多种损伤形式。电力检修记录和前期项目研究发现，电场会对金属结构在大气环境下的腐蚀产生显著影响，而这种影响势必会作用到微动腐蚀过程当中。为了深入认识这一微动损伤形式，本项目将对电场作用下钢芯铝绞线微动腐蚀损伤机理展开研究。.通过对导线的受力条件、所处的大气环境和电场环境参数进行分析，建立其损伤的科学研究体系。采用电化学测量方法结合表面分析和结构分析，研究电场条件下导线的微动腐蚀过程。对导线的微动腐蚀产物、微动磨损表面以及微动疲劳裂纹萌生区、扩展区和断裂区的特征进行观察分析，研究其微动损伤过程。通过宏微观试验研究，揭示电场和大气腐蚀耦合作用下钢芯铝绞线的微动损伤机理，为深入认识这一损伤形式和输电体系防护提供理论和方法支持。

钢芯铝绞线(ACSR)广泛应用于高压输电线路。服役中的ACSR导线在风致振动和大气腐蚀环境下会产生以微动腐蚀为主的多种损伤形式。电场会对金属结构在大气环境下的腐蚀产生显著影响，而这种影响势必会作用到微动腐蚀过程当中。为了深入认识这一微动损伤形式，本项目对电场作用下钢芯铝绞线微动腐蚀损伤机理展开了研究。.项目主要研究内容包括微动磨损和微动疲劳两个部分，着重研究了电场环境对导线微动腐蚀过程的影响规律。对导线的微动腐蚀产物、微动磨损表面以及微动疲劳裂纹萌生区、扩展区和断裂区的特征进行了观察分析，研究了其微动损伤过程。.研究表明：(1)铝股线各层受到的应力由内到外依次降低。内层铝线在受到较大应力的情况下微动腐蚀磨损，发生疲劳的可能性更高。建立了导线的有限元模型，得到了接触区域的分布规律。(2)在相同的接触载荷下，增大位移幅值，塑性变形增强，导线表面的接触区域凹凸不平，颗粒堆积现象明显，接触表面在滑动方向有犁沟现象产生，微动区域由部分滑移区向混合区、滑移区转变；在相同位移幅值下，增大接触载荷，接触区域中心发生粘着，接触边缘发生塑性变形，微动区域由滑移区向混合区、部分滑移区转变。(3)普通环境下，粘着磨损和磨粒磨损是主要微动磨损机制。腐蚀环境下，导线接触区域的摩擦力小于干摩擦环境中的摩擦力，但是由于腐蚀溶液的作用，在相同的微动周期内，磨损加剧，磨损体积增加。腐蚀环境下，都以磨粒磨损、腐蚀磨损和疲劳磨损为主。电场和腐蚀介质耦合环境下，受电离子的吸附作用，磨粒堆积于磨损表面，电场增强了腐蚀作用，铝线表面裂纹和坑洞分布更加密集。电场和腐蚀环境下钢芯铝绞线的微动腐蚀磨损机制为磨粒磨损、腐蚀磨损和疲劳磨损。（4）电场环境对铝股线疲劳寿命有显著影响。.通过宏微观试验研究，本项目揭示了电场和大气腐蚀耦合作用下钢芯铝绞线的微动损伤机理，为输电体系防护提供了理论和方法支持。