机械疲劳对40Cr钢显微组织的影响  

Influence of Mechanical Fatigue on Microstructure of 40Cr Steel

作　　者：吴益文[1] 任晨[2] 华沂[1] 徐凌云[1] 汪宏斌[2] 张聪[1,2] 

机构地区：[1]上海出入境检验检疫局,上海200135 [2]上海大学,上海200072

出　　处：《理化检验（物理分册）》2012年第11期709-712,共4页Physical Testing and Chemical Analysis(Part A:Physical Testing)

基　　金：国家质检总局科研项目(2011IK043)

摘　　要：以汽车曲轴常用材料40Cr钢为研究对象,用透射电镜对经过不同疲劳周次的试样进行显微组织观察,研究其显微组织与机械疲劳的对应关系。研究表明:在同一应力水平下,随着疲劳循环次数的增加,位错从晶界出发向晶内扩展,位错的形态由无规律的分布到形成位错条带,最后形成亚晶粒组织。机械疲劳循环次数与位错密度的函数关系为ρ=2.88×108 N+5.271 2×108。40Cr steel was researched as the common material used for automobile crankshaft. TEM was used to observe the change of microstructure, and to find the relationship between the change of microstructure and mechanical fatigue. The research results showed that, in the same stress level, with the fatigue cycle number increased, the dislocations in the 40Cr initiated from the grain boundaries, extended into the grain. And the morphology of the dislocation became to sub grains from bands. The dislocation density increasing caused by mechanical fatigue had liner relationship with fatigue cycle number. The relationship was. p=2.88X10^8N＋5.2712X10^8.

关 键 词：40CR钢 机械疲劳 显微组织 位错密度 

分 类 号：TG113.12[金属学及工艺—物理冶金]