文档介绍：第 33 卷第 5 期机
械
工
程
材
料 V ol. 33
N o. 5
2009 年 5 月 M aterials
for
M echanical
Eng ineering M ay
2009
40Cr 钢汽车半轴断裂失效分析
黄丽荣1 , 汤宏智2
( 1. 沈阳职业技术学院机械装备系, 辽宁沈阳 110045; 2. 沈阳华晨金杯汽车有限公司, 辽宁沈阳 110044)
摘
要: 通过宏观分析、显微组织和断口形貌观察以及硬度测试等方法对 40Cr 钢汽车半轴的断
裂原因进行了分析。结果表明: 汽车半轴断裂的主要原因是半轴凸缘与杆连接的轴台阶处表面存
在脱碳层, 在高的扭转疲劳剪切应力作用下形成裂纹源; 40Cr 钢含有较多的大尺寸非金属夹杂物,
另外热处理工艺不当, 造成材料综合力学性能达不到要求, 使表面萌生的裂纹在应力作用下迅速扩
展, 造成汽车半轴发生疲劳断裂。
关键词: 汽车半轴; 断裂; 40Cr 钢; 失效分析
中图分类号: T G142. 41
文献标志码: B
文章编号: 1000
3738( 2009) 05
0073
03
Failure Analysis of 40Cr Steel Automobile Semi
axle
HUANG Li
rong1 , TANG Hong
zhi2
( 1. Sheny ang Po lytechnic College, Shenyang 110045, China;
2. Shenyang Brilliance Jinbei Automobile Co. , Ltd, Shenyang 110044, China)
Abstract: U sing macro ana lysis, the o bservatio n of microstructure and fracture morpholog y and hardness
test ing , t he failure analy sis of breaking of 40Cr steel auto mobile semi
ax le w as analyzed. T he results show that the
crack w as mainly caused o f the deca rburized layer o n the surface o f axial bench co nnected half shaft flang e and rod,
the crack init iatio n w as formed under the hig h to rsio n fat igue shearing stress. T he 40Cr steel contained more no n
met allic inclusio ns, and its mechanical propert ies could not reach t he request as the impro per heat treatment pro cess.
T he fat igue crack formed o n