Restoration of Rolling Contact Fatigue Stress built up in Rolling Bearings

The restored service life of the used rolling bearings by level 1 remanufacturing process is shorter than that of new one. The UNSM (Ultrasonic Nanocrystal surface modification) has been applied to relieve and restore the fatigue stress of conventional rolling bearings. Test results of ball rolling contact specimens showed not only restoring fatigue strength, but enhancing service life more than the new one. Test results of commercial bearings will be explained with microstructural analysis and mechanical properties changing by UNSM.