某输电线路铁塔防坠T型导轨脱落原因  

Reason for the detachment of the anti fall T-shaped guide rail of a certain transmission line tower

作　　者：党乐 董俊谦 张威 崔亚茹 尚鑫 DANG Le;DONG Junqian;ZHANG Wei;CUI Yaru;SHANG Xin(Electric Power Research Institute,State Grid Inner Mongolia Eastern Electric Power Co.,Ltd.,Hohhot 010000,China)

机构地区：[1]国网内蒙古东部电力有限公司电力科学研究院,呼和浩特010000

出　　处：《理化检验(物理分册)》2025年第4期69-74,共6页Physical Testing and Chemical Analysis(Part A:Physical Testing)

摘　　要：某1000 kV输电线路铁塔防坠T型导轨发生脱落事故。采用宏观观察、几何尺寸测量、金相检验、扫描电镜及能谱分析、力学性能测试、化学成分分析等方法分析了导轨脱落的原因。结果表明:使用的连接板材料与设计不符,连接板材料组织中存在大量三次渗碳体及较严重的非金属夹杂物,造成连接板强度降低、脆性变大、抗疲劳能力降低;同时,连接板上螺栓孔冲孔工艺不当,存在多余开孔,在螺栓孔边缘形成裂口;在运行过程中,螺栓孔边缘发生疲劳开裂,导致连接板沿螺栓孔彻底断裂,最终造成导轨脱落。The anti fall T-shaped guide rail of a 1000 kV transmission line tower fell off.The reasons for the detachment of the guide rail were analyzed using macroscopic observation,geometric dimension measurement,metallographic examination,scanning electron microscopy and energy spectrum analysis,mechanical property testing and chemical composition analysis.The results show that the connecting plate material used did not match the design,and there were a large number of tertiary carbides and severe non-metallic inclusions in the structure of the connecting plate material,resulted in a decrease in the strength of the connecting plate,an increase in brittleness,and insufficient fatigue resistance.At the same time,the punching process for the screw holes on the connecting plate was improper,resulted in excess holes and the formation of cracks at the edges of the bolt holes.During operation,fatigue cracking occurred at the edge of the bolt hole,causd the connecting plate to completely break along the screw hole,ultimately resulted in the detachment of the guide rail.

关 键 词：防坠T型导轨 L型连接板 脱落 渗碳体 非金属夹杂物 开孔 

分 类 号：TB31[一般工业技术—材料科学与工程] TG115.2[金属学及工艺—物理冶金]