ROLLING CONTACT FATIGUE CHARACTERISTICS OF SAE52100 BY ULTRASONIC NANOCRYSTAL SURFACE MODIFICATION TECHNOLOGY

Abstract

UNSM(Ultrasonic Nanocrystal Surface Modification) technology has been applied to test specimens of bearing rings and rollers made of SAE52100. Mechanical properties, especially rolling contact fatigue characteristics, are analyzed using two-roller test and 6-ball test before and after UNSM treatment. The main effects to improve rolling contact fatigue characteristics by UNSM treatment are explained in the view points of residual stress, hardness and surface topology.