调质态40Cr钢旋转弯曲疲劳寿命与显微组织的关系  

Rotate Bending Fatigue Life and Microstructure of Quenched and Tempered 40Cr steel

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

机构地区：[1]上海出入境检验检疫局国家再制造机械产品检测实验室,上海200135 [2]上海大学材料科学与工程学院,上海200072

出　　处：《中国表面工程》2012年第5期90-95,共6页China Surface Engineering

基　　金：国家质检总局2011年科研项目(2011IK043)

摘　　要：文中对调质态的40Cr钢进行了旋转弯曲疲劳试验,采用透射电镜对经过不同的旋转弯曲疲劳试验阶段的试样进行微观分析,并测定了不同疲劳阶段试样内部的位错密度。结果表明:开始时位错从晶界萌生,向晶内扩展,形成亚晶粒组织。随着旋转弯曲疲劳循环次数增加,位错密度逐渐增加,晶内碳化物也发生明显变形以至破裂。建立位错密度与旋转弯曲疲劳之间的数学方程式,旋转弯曲疲劳所引起的位错密度增殖与疲劳循环次数呈线性正比关系,函数公式为ρ=2.0108×108 N-1.914×108,R2=0.98193。研究结果可供无损检测法制订再制造毛坯剩余寿命判据参考。The rotating bending fatigue testing was carried out on the quenched and tempered 40Cr, and mi crostructure and the inner dislocation density during different rotating bending fatigue states were analyzed by transmission electron microscopy （TEM）. The results shows that dislocations in the quenched and tempered 40Cr initiate form the grain boundaries extending into the grain, and the subgrains form. With the increaseing number of cycles for rotary bending fatigue, the carbide begins to deform measurably and is destroyed into micro-cracks. A mathematical model is set up to describe the relationship between dislocation density and ro tary bending fatigue times. The density of the increasing dislocations caused by rotating bending fatigue has a linear relationship with the fatigue cycle number. The function formula is p=2.0108×10^8N-1.914×10^8,R^2=0.98193. The above findings may be used as criteria references for non-destructive testing on the remaining life of remanufacturing blanks.

关 键 词：再制造坯件 40CR钢 显微组织 位错密度 疲劳寿命 

分 类 号：TG115.57[金属学及工艺—物理冶金] TH17[金属学及工艺—金属学]