城轨地铁车辆牵引齿轮渗碳层裂纹失效分析  

Failure Analysis of Carburizing Layer Crack in Traction Gear of Metro Vehicles

作　　者：殷桂明 吴国文 罗志勇 YIN Guiming;WU Guowen;LUO Zhiyong(Guangzhou Metro Operation Headquarter,Guangzhou 510700 Guangdong,China)

机构地区：[1]广州地铁集团有限公司运营事业总部,广州510700

出　　处：《铁道机车车辆》2020年第5期121-125,共5页Railway Locomotive & Car

摘　　要：针对城轨地铁A2型车辆牵引齿轮箱从动齿轮——18CrNiMo7-6渗碳斜齿轮表面裂纹进行分析,利用磁粉检测、宏观检验、材质及金相组织分析、断口微观分析等方法,检测并查找齿面起裂原因。结果表明,同批次故障从动齿轮的裂纹侧和非裂纹侧渗碳层深度存在明显差异,同时通过有效硬化层的硬度梯度测试印证该差异性,测量有裂纹侧的齿面淬火硬化层深度(CHD),低于原始制造技术要求,因此,推测渗碳层的差异性及渗碳淬硬层深度不符要求,导致齿面局部强度不足,是故障齿轮沿渗碳层开裂的主要原因。In this paper,based on the detection of driven bevel gear(material 18CrNiMo7-6)surface cracks in batch of traction gear box of A2 metro vehicles,the causes of cracks are analyzed through material analysis,macro inspection,fracture micro analysis and metallographic analysis.The results showed that the carburizing layer depth on the crack side and the non-crack side of the fault driven gear in the same batch was significantly different.The difference was confirmed by the hardness gradient test of the effective hardening layer.And the depth of quenching layer(CHD)on the gear surface of the crack side was detected,it was lower than the original manufacturing technical requirements.Therefore,it is speculated that the difference of carburizing layer depth and the depth of quenching layer does not meet the requirements,which is the main reason for the failure of gear surface local strength is insufficient,Long-term operation produces cracking along the carburized layer.

关 键 词：斜齿轮 表面裂纹 渗碳层深度 渗碳淬硬层深度CHD 

分 类 号：U239.5[交通运输工程—道路与铁道工程]