小型汽车发动机连杆弯曲失效分析  

Bending failure analysis of connecting rod of small-sized automobile engine

作　　者：段莉萍[1] 陈耘[1] 张维贤 唐家耘[1] 

机构地区：[1]中国兵器科学研究院宁波分院,浙江宁波315103 [2]总装备部装甲兵军事代表局,北京100851

出　　处：《兵器材料科学与工程》2012年第6期85-87,共3页Ordnance Material Science and Engineering

摘　　要：小型汽车发动机活塞连杆组在使用过程中连杆发生弯曲。对活塞连杆组中各组成零件的状态、表面形貌等进行宏观分析;对连杆进行化学成分、表面缺陷、显微组织缺陷和金相组织分析。结果表明:发动机活塞连杆组出现异常,主要是由于连杆发生弯曲变形,工字型部位存在表面折叠、表面脱碳、带状组织和较严重的非金属夹杂物等缺陷,降低了42CrMo钢的刚度和抗弯强度,导致连杆弯曲变形失效。A connecting rod of small-sized automobile engine was bended in the driving service. The macroscopic analysis of state and surface morphology of the component parts in piston- connecting rod was carried out. The chemical composition, metallurgical structure, surface and microstructure defects of connecting rod were analyzed. The results show that there exists surface puckerings, surface decarbonization, banded structures and nonmetallic inclusions in the I- shaped position of connecting rod. It is concluded that the abnormal condition of piston-connecting rod is mainly caused by the bending deformation of connecting rod. Surface puckerings, surface decarbonization and banded structures in the connecting rod reduce the mechanical performance of 42CrMo steel, which results in the failure of connectin. rod.

关 键 词：连杆 表面缺陷 带状组织 弯曲 

分 类 号：TG115.213[金属学及工艺—物理冶金]