Fretting behaviors of a steel up to very high cycle fatigue

Abstract

In the present work, the fretting fatigue behaviors of GCr15 steel (Chinese GB/T-standard) have been studied up to the very high cycle fatigue (VHCF) regime by using an ultrasonic fatigue system. The main aims of the investigations were the analyses of S–N curves, worn morphology, as well as fracture morphology. As expected, the results of the fretting fatigue tests show a reduction in the lifetime compared to plain fatigue tests without fretting. 2-D and 3-D morphologies of the fretting worn surfaces are combined to study the evolution of the stick zone. With the increasing fatigue life, the stick zone will fully occupy the whole worn zone. Besides, fretting causes severe oxidation and debris in the worn surface. The crack initiation depth increases with the increase in fatigue life, especially in the VHCF regime, the depth increases drastically because of fretting delamination.