减速机齿轮轴断齿原因分析

Analysis of the gear shaft broken teeth of the reducer

针对减速机齿轮轴发生断齿现象,进行了化学成分分析,利用金相分析技术研究了齿轮轴内部微观组织结构以及产生缺陷的原因,采用扫描电镜观察断口形貌特征,以及通过硬度计算方法计算了齿部的硬化层深度,并对齿顶渗碳淬火硬化层进行了数学校验。结果表明,由于齿轮在淬火加热时温度过高,导致齿轮内部出现粗大马氏体及网状碳化物,齿面存在严重的内氧化现象致使齿部材料脆化,进而出现沿晶裂纹和掉块,并且在齿轮轴存在安装偏载且硬度偏低的协同作用下发生断齿现象。

Aiming at the broken phenomenon of the gear shaft in a reducer,the chemical composition of the gear shaft was analyzed;the internal microstructure of the gear shaft and the causes of defects were studied by metallographic analysis technology.The fracture morphology was observed by scanning electron microscope,and the hardened layer depths of the tooth were calculated by the hardness calculation method,and the carburized and quenched hardened layers on the tooth top were mathematically verified.The results show that the high temperature of the gear during quenching and heating leads to the appearance of coarse martensite and network carbide in the gear.There is a serious internal oxidation phenomenon on the tooth surface,resulting in the embrittlement of the tooth material,and then intergranular cracking and blocks falling.In addition,the phenomenon of broken teeth occurs under the synergistic effect of the eccentric loads and low hardness.