谐波减速器服役过程中柔轮断裂失效原因分析与工艺改进
Fracture Analysis of Toughness Fracture Failure on Flexspline of Harmonic Reducers During the Service
穆晓彪 1张永奇 2高明艳 1杨国强 1张朝磊2
作者信息
- 1. 北京中技克美谐波传动股份有限公司,北京 101318
- 2. 北京科技大学 材料科学与工程学院,北京 100083
- 折叠
摘要
通过显微组织的观察分析、断口形貌的观察和硬度测定,分析造成柔轮疲劳断裂失效的原因.结果表明,失效柔轮的显微组织为回火屈氏体,柔轮上存在较严重的3级带状组织.虽然存在MnS和Al2O3夹杂物引起的4.42 μm微孔,但由于其尺寸和数量较小,不是导致其断裂的主要原因.样品的晶粒整体上较粗大,断口裂纹处晶粒更粗大且更不均匀,断口裂纹处的晶粒尺寸是远离断口晶粒的1.4倍.晶粒粗大使晶界面积减小,导致塑性变形不均匀,易产生应力集中,从而产生初生裂纹,同时也不利于阻碍裂纹的扩展,导致样品发生断裂失效.因此,原奥氏体晶粒粗大是导致柔轮疲劳断裂主要原因.可通过循环热处理或增加正火预处理,达到细化晶粒的作用.
Abstract
The reasons of the fatigue failure of flexspline are analyzed by observation analysis,observation and hardness determination of fracture morphology of microstructure.The results show that the micro-structure of the flexspline of the failed harmonic reducer are tempered troostite,and there is more severe grade 3 banded structure on the flexspline.Al-though the 4.42 μm micropores caused by MnS and Al2O3 inclusions exist,they are not the main cause of breakage due to its small size and number.Meanwhile the overall grain size of the sample,especially the grain size at fracture crack,is coarse,and the grain at the fracture crack is thicker and more uneven.the grain size at the fracture crack is 1.4 times that away from the fracture grain.The coarse grain assembly leads to smaller grain boundary area,which not only leads to more uneven plastic deformation,but also more prone to stress concentration,which causes primary cracks,and is difficult to hinder crack expansion,resulting in fracture failure of the sample.Therefore,the primary austenite grain is the main cause for fatigue fracture of flexspline.The grain refinement can be achieved by circulating heat treatment or adding normalizing pretreatment.
关键词
谐波减速器/柔轮/断裂失效Key words
Harmonic Reducer/Flexspline/Fracture Failure引用本文复制引用
出版年
2024
NETL
NSTL
维普
万方数据