The evaluation of fretting fatigue life for INCONEL 600 and 690 alloy

The initial crack under fretting condition occurs at lower stress amplitude and at lower cycles of cyclic loading than that under plain fatigue condition. INCONEL alloy 600 and 690 are high-chromium nickel alloy having excellent resistance to many corrosive aqueous media and high-temperature atmospheres. In this paper, the effect of fretting damage on fatigue behavior for INCONEL alloy 600 and 690 were studied. Also, various kinds of mechanical tests such as hardness, tension and plain fatigue tests are performed. Fretting fatigue tests were carried out with flat-flat contact configuration using a bridge type contact pad and plate type specimen. Through these experiments, it is found that the fretting fatigue strength decreased about 40-70% compared to the plain fatigue strength in two materials. In fretting fatigue, the wear debris is observed on the contact surface, and the oblique micro-cracks at an earlier stage are initiated. These results can be used as basic data in a structural integrity evaluation of heat and corrosion resisting alloy considering fretting damages.