Crack growth and microstructural changes in AISI 52100: white etching cracks (WEC) and fine granular area (FGA)
Crack growth and microstructural changes in AISI 52100: white etching cracks (WEC) and fine granular area (FGA)
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AISI 52100 中的裂纹扩展和微观结构变化：白色蚀刻裂纹 (WEC) 和细颗粒区域 (FGA)
DOI：
10.1051/matecconf/201930018001
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发表时间：
2019
影响因子：
--
通讯作者：
E. Kerscher
中科院分区：
文献类型：
--
作者：
S. Averbeck;D. Spriestersbach;E. Kerscher
滚动轴承的使用寿命通常可以很好地预测。然而，损坏现象“白色蚀刻裂纹”（WEC）可导致过早和不可预见的失效。在裂纹面处形成具有强烈减小的晶粒尺寸的区域是这种类型的失效的特征。早期的研究表明，这是可能的，重现这种类型的失败，多轴疲劳实验与叠加循环压缩和扭转。本研究显示了这些多轴疲劳试验的应力状态与基于应力的临界平面准则的分析。使用临界平面的结果作为断裂力学分析的基础，发现裂纹长度，相关的塑性区的大小，和转化的微观结构的程度之间的相关性。这种相关性是非常相似的细颗粒区（FGA），在轴承钢中的一个非常高的循环疲劳现象的研究结果。有人认为，塑性驱动的机制类似于FGA形成的一个建议是负责WEC的形成，太。经常被引用为促进WEC形成的其他因素可以解释从FGA情况下的极高循环疲劳到由于WEC导致的早期失效的转变。
The service life of rolling element bearings can usually be predicted with good accuracy. However, the damage phenomenon „white etching cracks” (WEC) can lead to premature and unforeseeable failures. The formation of zones with strongly decreased grain sizes at the crack faces is a characteristic of this type of failure. An earlier study showed that it is possible to reproduce this type of failure by multiaxial fatigue experiments with superposed cyclic compression and torsion. The present study shows the analysis of the stress state of those multiaxial fatigue tests with stress-based critical plane criteria. Using the critical plane results as a basis for a fracture mechanical analysis, a correlation is found between the crack length, the associated plastic zone size, and the extent of the transformed microstructure. This correlation is very similar to our results of the study of fine granular areas (FGA), a very high cycle fatigue phenomenon in bearing steels. It is argued that a plasticity-driven mechanism similar to the one proposed for FGA formation is responsible for WEC formation, too. Additional factors that are often cited as promoting WEC formation could explain the shift from very high cycle fatigue in the case of FGA to the early failures due to WEC.