卡车柴油机高压油管开裂分析  

Failure Analysis on High Pressure Fuel Pipes Used in Truck Diesel Engine

作　　者：李旭东 于志伟[1] 许晓磊[1] LI Xu-dong;YU Zhi-wei;XU Xiao-lei(Department of Material Science and Engineering,Dalian Maritime University,Liaoning Dalian 116024,China)

机构地区：[1]大连海事大学材料科学与工程系,辽宁大连116024

出　　处：《失效分析与预防》2018年第2期119-123,共5页Failure Analysis and Prevention

摘　　要：多批次卡车柴油机高压油管在服役中过早发生开裂,利用体视显微镜、扫描电子显微镜对开裂高压油管的裂纹形态及断口表面进行观察。结果表明:高压油管的失效模式均属于疲劳开裂;裂纹起源于内孔清理喷丸过程中形成的纵向微切削损伤,在内孔油压导致的环向拉应力作用下,疲劳裂纹从油管内表面向外表面扩展,最终导致油管开裂漏油。The high pressure fuel pipes used in truck diesel engine cracked in service.The crack morphology and fracture surfaces of cracked fuel-pipes were observed by stereomicroscope and scanning electron microscope.The results indicate that the failure mode of all the fuel-pipe was fatigue fracture.The crack origin was originated from the m icro-cutting marks on the internal surface due to grit-blasting for cleaning internal hole.The crack propagated from the internal surface toward the external surface under the circum ferential tensile stress due to the operating oil-pressure in the internal hole to lead to fatigue.

关 键 词：柴油机 高压油管 疲劳开裂 微切削损伤 

分 类 号：U464.172[机械工程—车辆工程]