高压共轨喷油嘴针阀体开裂失效分析  

Failure Analysis on Cracking of High Pressure Common Rail Fuel Nozzle

作　　者：何静[1] 郑鑫[1] 沈亚冬 黄俊[1] 张武凯[1] 王树平 HE Jing;ZHENG Xin;SHEN Yadong;HUANG Jun;ZHANG Wukai;WANG Shuping(FAW Wuxi Fuel Injection Equipment Research Institute, Wuxi 214063, China)

机构地区：[1]中国一汽无锡油泵油嘴研究所,江苏无锡214063

出　　处：《现代车用动力》2018年第1期39-43,共5页Modern Vehicle Power

摘　　要：对某型高压共轨喷油嘴针阀体开裂问题进行了失效分析,通过有限元结构分析、扫描电镜断口分析、金相组织分析及显微硬度检测等多方面研究,指出针阀体是在较高的压力波动疲劳载荷条件下,显微裂纹从进油道与中孔之间下部尖角处起始并快速扩展导致沿晶疲劳开裂,针阀体渗碳层显微硬度过高是开裂的主要原因,提出了满足160 MPa共轨系统针阀体的工艺技术要求改进建议。Failure analysis has been carried out on the cracking of high pressure common rail nozzle body. Finite element structural analysis,SEM fractography,metallographic analysis and microhardness measurements were performed to figured out the root cause of failure. It has been concluded that the micro crack was initiated from the bottom tip area between the fuel inlet hole and center hole and then propagated along gain boundaries,resulting an intergranular cracking. Excessively high microhardness of the nozzle body is the main reason for the cracking failure. Following the investigation,recommendations for improvement of manufacturing technical requirements was proposed to meet the 160 MPa pressure level common rail nozzle body.

关 键 词：喷油嘴 进油道 开裂 失效分析 显微硬度 

分 类 号：TK423.8[动力工程及工程热物理—动力机械及工程]