SCM435钢摇臂螺栓断裂原因  

Causes of fracture of SCM435 steel rocker bolt

作　　者：吕金峄 王勤 李亚洲 贾川 郭明仪 LYU Jinyi;WANG Qin;LI Yazhou;JIA Chuan;GUO Mingyi(Henan Jiyuan Iron&Steel(Group)Co.,Ltd.,Jiyuan 459000,China)

机构地区：[1]济源钢铁(集团)有限公司,济源459000

出　　处：《理化检验（物理分册）》2024年第6期37-41,共5页Physical Testing and Chemical Analysis(Part A:Physical Testing)

摘　　要：某汽车发动机SCM435钢摇臂螺栓在试验过程中发生断裂现象。采用宏观观察、化学成分分析、金相检验、硬度测试、扫描电镜分析等方法对螺栓的断裂原因进行分析。结果表明:摇臂螺栓的化学成分和硬度均符合产品要求,显微组织无异常;摇臂螺栓在使用过程中发生偏载,承受了超出其疲劳强度的异常弯曲应力,最终导致材料疲劳断裂。The SCM435 steel rocker bolt of an automobile engine fractured during the test.The causes of bolt fracture were analyzed by means of macroscopic observation,chemical composition analysis,metallographic examination,hardness test,scanning electron microscopy analysis.The results show that the chemical composition and hardness of the rocker bolt met the product requirements,and the microstructure was normal.The rocker bolt was eccentrically loaded during use,and it bore abnormal bending stress exceeding its fatigue strength,which eventually led to fatigue fracture of the material.

关 键 词：SCM435钢 摇臂螺栓 弯曲应力 显微组织 偏载 断裂 

分 类 号：TG115.2[金属学及工艺—物理冶金] TB31[金属学及工艺—金属学]