柴油机高压共轨喷油器针阀体裂纹分析  

Crack analysis of needle body of diesel engine high pressure common rail injector

作　　者：耿旭 王光明 刘明 贾小丽 李慧慧 GENG Xu;WANG Guangming;LIU Ming;JIA Xiaoli;LI Huihui(State Key Laboratory of Engine and Powertrain System,Weifang 261061,China;Weichai Power Co.,Ltd.,Weifang 261061,China)

机构地区：[1]内燃机与动力系统全国重点实验室,山东潍坊261061 [2]潍柴动力股份有限公司,山东潍坊261061

出　　处：《内燃机与动力装置》2024年第5期87-91,共5页Internal Combustion Engine & Powerplant

基　　金：国家重点研发计划项目(2021YFD2000300)。

摘　　要：为解决喷油器针阀体肩胛圆角处开裂故障,采用扫描电子显微镜、能谱分析仪、显微硬度检测、计算机断层扫描等方法分析故障原因及失效机理并提出解决方案。结果表明:失效位置表面含有S、Cl等腐蚀性元素,裂纹表面存在多处不规则腐蚀坑,裂纹处维氏硬度比肩胛处降低了28%,最小壁厚比正常件减小了47%,腐蚀性裂纹是导致针阀体失效的主要原因。可采用使用符合国家标准的燃油及在针阀体表面增加涂层等解决针阀体腐蚀失效问题。To solve the problem of cracking at the scapular corner of the injector needle valve body,methods such as scanning electron microscope,energy dispersive spectrometer,microhardness testing,and CT are used to analyze the cause and failure mechanism of the fault,and solutions are proposed.The results show that the surface of the failure site contained corrosive elements such as S and Cl,and there are multiple irregular corrosion pits on the crack surface.The Vickers hardness at the crack site decreased by 28%than that at the scapular corner of the needle valve body,and the minimum wall thickness decreased by 47%compared to the normal part,and the main cause of needle valve body failure is corrosive cracks.Use fuel that meets national standards and add coatings on the surface of the needle valve body can solve the problem of needle valve body corrosion failure.

关 键 词：柴油机 针阀体 裂纹 腐蚀 喷油器 

分 类 号：TK423.8[动力工程及工程热物理—动力机械及工程]