摘要
针对某型柴油机气门在运行2 000 h后发生的失效问题,对失效的气门进行宏观与微观断口、金相、材料成分、硬度等全面分析。结果表明,排气门杆部上侧为首断件,排气门下侧盘部是后断件。排气门的断裂模式为疲劳断裂,源区位于摩擦焊位置的内部。排气门发生疲劳断裂的主要原因是焊缝位置存在较大的C类夹杂物导致疲劳源的产生进而发生疲劳断裂。
Here were analyzed the macroscopic and microscopic fractures,metallographic structure,chemical components and hardness of the exhaust valve of diesel engine of a certain type. The results showed that the upside of the exhaust valve rod fractured first and the underside ensued. The fracture of exhaust valve was fatigue fracture,and the original fracture region was located in the inside of the friction welding position. The main reason for the fatigue fracture of the exhaust valve was the existence of carbon inclusion which led to the generation of fatigue source in the welding seam.
作者
刘鹏
吴亚龙
王生龙
LIU Peng;WU Yalong;WANG Shenglong(Military Representative Office of the Navy in Luoyang Four Zero Seven Factory, Luoyang 471033, China;Henan Diesel Engine Heavy Industry Co Ltd, Luoyang 471033, China;Luoyang Ship Material Research Institute, Luoyang 471023, China)
出处
《材料开发与应用》
CAS
2018年第1期64-71,共8页
Development and Application of Materials
关键词
柴油机
气门
疲劳断裂
diesel engine
exhaust valve
fatigue fracture
