摘要
某型液压挖掘机的销轴在作业过程中发生断裂。采用宏观观察、金相组织分析、硬度检测、化学成分分析、力学性能检验手段对销轴的断裂原因进行了综合分析。结果表明:失效销轴属于典型脆性断裂,工作时间较短,属于早期失效;活塞杆和连杆对销轴挤压,在销轴表面形成应力集中以及表面淬火不合格是导致销轴脆断的主要原因;另外,调质处理不符合要求,销轴强度低也是销轴早期断裂的重要原因。该分析结果为失效销轴的改进提供了有力的依据。
A hydraulic excavator pin fractured during service.The investigation on the fractured pin was carried out by macro analysis,microstructure analysis,hardness testing,chemical composition analysis and mechanical properties testing.The results show that the fracture of the pin is typical brittle fracture and belongs to early failure.The extrusion from the piston rod and connecting rod to the pin caused stress concentration at the surface of the pin.Surface stress concentration and poor quenching quality are the main cause of the fracture of the pin.In addition,the lower strength of the pin due to improper quenching and tempering treatment is another cause for the early failure.The analysis results lay a solid foundation for the improvement of the pin.
出处
《失效分析与预防》
2011年第3期164-168,共5页
Failure Analysis and Prevention
关键词
液压挖掘机
销轴
脆性断裂
疲劳失效
热处理
hydraulic excavator
pin
brittle fracture
fatigue failure
heat treatment
