GCr15钢超声微动疲劳性能研究

由微动产生的裂纹萌生对钢组件的疲劳强度具有重要影响。本文选择GCr15轴承钢,在20kHz超声疲劳试验机提供的循环载荷作用下,测试其超长寿命微动疲劳性能。试验结果显示,在109循环周次下微动疲劳强度影响因子达到0.37。通过电子扫描电镜观察试件磨损面和微动疲劳断口,并分析了高频超长寿命微动疲劳断裂机理。高周疲劳裂纹通常会在磨损面的粘着区与滑移区交界处萌生,超高周疲劳裂纹在粘着区内萌生。微动磨损面的面积以及磨损面的粘着区都随着试件疲劳寿命的增加而增加。

On the Ultrasonic Fretting Fatigue Properties of GCr15 Steel

Crack initiation induced by fretting may have a significant influence on fatigue strength of steel components.In this paper,selecting GCr15 bearing steel as study object,its fretting fatigue properties was measured,based on 20kHz ultrasonic fatigue test machine.Results show that at 109 cycles,the influence factor of fretting fatigue strength reaches 0.37.The worn surface and fretting fracture surface of specimens were observed by scanning electron microscope,and the fracture mechanism of fretting fatigue in ultra long life was analyzed.Crack initiation occurs normally at the boundary between stick and slip zone on worn surface under high cycle condition;however,under VHCF condition,all the cracks are initiated in the stick zone.The area of worn surface and its stick zone area increase with the increase of specimen's fatigue life.