某高压断路器齿轮轴断齿原因  

Reason for gear shaft tooth breakage of a certain high-voltage circuit breaker

作　　者：杜书万 李纪强 段永磊 李晓征 王海燕 DU Shuwan;LI Jiqiang;DUAN Yonglei;LI Xiaozheng;WANG Haiyan(Henan Pinggao Electric Co.,Ltd.,Pingdingshan 467000,China)

机构地区：[1]河南平高电气股份有限公司,平顶山467000

出　　处：《理化检验（物理分册）》2024年第11期67-70,共4页Physical Testing and Chemical Analysis(Part A:Physical Testing)

摘　　要：某高压断路器在300次开合试验后动作异常,对其进行解体后发现一级齿轮轴发生断齿现象。采用宏观观察、化学成分分析、硬度及渗碳层深度测试、金相检验、扫描电镜及能谱分析等方法对齿轮轴断齿原因进行分析。结果表明:渗碳时温度及碳势偏高,导致组织中产生粗针状马氏体和网状碳化物,使材料的脆性增大;齿轮轴在转动过程中,首先在齿根脆性相附近产生显微裂纹,在应力作用下,裂纹沿晶界进一步扩展,最终导致齿轮轴发生沿晶断裂。A certain high-voltage circuit breaker operated abnormally after 300 opening and closing tests,and upon disassembly,it was found that the first gear shaft had broken teeth.The reasons for gear shaft tooth breakage were analyzed using macroscopic observation,chemical composition analysis,hardness and carburizing layer depth testing,metallographic examination,scanning electron microscopy and energy spectrum analysis.The results show that during carburizing,the temperature and carbon potential were too high,resulting in the formation of coarse needle like martensite and network carbides in the microstructure,which increased the brittleness of the material.During the rotation of the gear shaft,microcracks first appear near the brittle phase at the tooth root.Under stress,the cracks further propagate along the grain boundaries,ultimately led to intergranular fracture of the gear shaft.

关 键 词：齿轮轴 碳势 粗针状马氏体 网状碳化物 沿晶断裂 

分 类 号：TG115.2[金属学及工艺—物理冶金] TB31[金属学及工艺—金属学]