【摘要】 针对高速列车制动系统试验中出现的杠杆断裂问题,采用电镜扫描技术对断裂杠杆进行了断裂区域分析,采用结构有限元分析识别了高应力区,通过不同加工与热处理工艺下的晶粒度和显微组织分析,配合疲劳试验对比验证,得到杠杆疲劳断裂的主要原因有线切割加工存在断线与沟纹尖角和热处理工艺不稳定导致晶粒度粗大、组织不稳定、脱碳等引起的应力集中;提出了加工与热处理的工艺优化方案及控制方法,试验结果表明杠杆平均疲劳寿命均达到200万次以上,满足制动夹钳单元的使用要求.更多还原

【Abstract】 Aiming at the problem of lever fracture in high-speed train brake system test,the fracture zone was analyzed by using scanning electron microscope technology,and the high stress zone was identified by the structural finite element analysis. To obtain the main reasons of fatigue fracture of the lever,the grain size and micro-organization analysis with different processing technologies and heat treatment were carried out,combined with the fatigue test comparison and verification. It turned out that there exists wire breaking during wire cutting and sharp corners. Also heat treatment process is instable. They lead to coarse grain size,instability,decarburization and other issues leading to stress concentrations. The process optimization scheme and control methods of machining and heat treatment are proposed. The test results show that the average fatigue life of the levers reaches more than 2 million times,which meets the requirement of the brake clamp unit.更多还原