摘要
对某型TBD234船用柴油机工作过程中出现的气阀断裂故障进行分析,从气阀结构、断口形貌和金相组织等方面进行故障原因分析,并提出改进建议。结果表明:气阀阀杆加工过程中表面存在的细微裂痕是疲劳断裂的源头,在柴油机燃烧室的循环热应力和弹簧作用力的影响下产生应力集中;燃烧气体中的腐蚀物质作用于裂痕内,加快了裂纹的扩展,最终导致气阀杆断裂。
The fault of air valve fracture in a TBD234 marine diesel engine is analyzed.The causes of fault are analyzed from the aspects of valve structure,fracture morphology and metallographic structure,and suggestions for improvement are put forward.The results show that the subtle cracks on the surface of the valve stem are the source of fatigue fracture,and the stress concentration is generated under the influence of the cyclic thermal stress and the spring force in the combustion chamber of the diesel engine.In addition,the corrosive substances in the combustion gas act on the cracks,speeding up the crack propagation,and finally leading to the fracture of the valve stem.
作者
栾鑫
陈海龙
张宏宇
LUAN Xin;CHEN Hailong;ZHANG Hongyu(Department of Mechanical and Electrical Management,Marine Police College,Ningbo 315800,Zhejiang,China)
出处
《机电设备》
2024年第4期67-72,共6页
Mechanical and Electrical Equipment
关键词
气阀故障
断裂力学
应力集中
金相组织
valve fault
fracture mechanics
stress concentration
metallographic structure
