| 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 N1.914×108，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。 |
| 关键词: 再制造坯件 40Cr钢 显微组织 位错密度 疲劳寿命 |
| DOI： |
| 分类号: |
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| Rotate Bending Fatigue Life and Microstructure of Quenched and Tempered 40Cr steel |
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WU Yiwen1, WANG Hongbin2, HUA Yi1, WANG Yingchun1,2, XU Lingyun1, JI Jing1, REN Chen1,2
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1. National Manufacturing Machinery Products Inspection Lab, Shanghai EntryExit Inspection & Quarantine Bureau, Shanghai 200135; 2. College of Materials Science and Engineering, Shanghai University, Shanghai 200072
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| Abstract: |
| The rotating bending fatigue testing was carried out on the quenched and tempered 40Cr, and microstructure 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 microcracks. A mathematical model is set up to describe the relationship between dislocation density and rotary 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 ρ=2.0108×108 N1.914×108, R2=0.98193. The above findings may be used as criteria references for nondestructive testing on the remaining life of remanufacturing blanks. |
| Key words: remanufacturing blank 40Cr steel microstructure dislocation density fatigue life |
