某型电机轴开裂原因  

Cracking causes of a certain type of motor shaft

作　　者：陈燕 CHEN Yan(Taifu Special Steel Suspension(Chengdu)Co.,Ltd.,Chengdu 610500,China)

机构地区：[1]泰富特钢悬架(成都)有限公司,成都610500

出　　处：《理化检验（物理分册）》2024年第5期42-45,共4页Physical Testing and Chemical Analysis(Part A:Physical Testing)

摘　　要：某型电机在使用过程中振动异常,停机检查发现电机轴表面存在裂纹。采用宏观观察、化学成分分析、金相检验、力学性能测试、扫描电镜分析等方法研究了该电机轴开裂的原因。结果表明:电机轴断口呈多源疲劳快速扩展特征形貌;堆焊工艺不当,使堆焊层硬度较低,且形成了脆性较大的自回火马氏体;在运转过程中,电机轴主要承受扭转载荷,轴表面所受应力最大,因此优先在轴表面堆焊层形成微裂纹,裂纹在扩展过程中汇聚形成多源疲劳,并在扭矩作用下裂纹呈八字形扩展,最终导致电机轴发生开裂现象。A certain type of motor vibrated abnormally during use,and during shutdown inspection,cracks were found on the surface of the motor shaft.The reasons for the cracking of the motor shaft were studied using methods such as macroscopic observation,chemical composition analysis,metallographic examination,mechanical performance testing and scanning electron microscopy analysis.The results show that the fracture surface of the motor shaft exhibited a characteristic morphology of rapid propagation of multi source fatigue.Improper welding process resulted in lower hardness of the welding layer and the formation of brittle self tempered martensite.During operation,the motor shaft mainly bore torsional load,and the surface of the shaft was subjected to the maximum stress.Therefore,microcracks were preferentially formed on the surface of the shaft by welding.During the propagation process,cracks converged to form multiple fatigue sources,and under the action of torque,the crack propagated in an eight-shaped shape,ultimately led to the occurrence of cracking in the motor shaft.

关 键 词：电机轴 堆焊层 多源疲劳 开裂 自回火马氏体 脆性 

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]