Effect Of Ultrasonic Frequency On Giga-cycle Fatigue Properties Of Steel

The component parts of railway rolling stocks, automobiles, bridges, engines, aviation and aerospace machinerys, generators and marine devices are supposed to endure109times of alternating loading during their service lives. In order to ensure the safety and reliability of these devices’bearing components, it is necessary to study their performance of giga-cycle fatigue. The regular experiment methods requires long period and high expense while the ultrasonic loading requires shorter period and less cost. But wether it’s appropriate to research steel material’s giga-cycle fatigue with ultrasonic experiment methods is not proved. Therefore, it’s necessary to prove it. This paper made a comparative study for the35CrMo axle steel and GCr15bearing steel’s giga-cycle fatigue properties with80Hz axial fatigue loading frequency and20Hz axial fatigue loading frequency, and used continuous loading system in ultrasonic fatigue test.The result of observing the fracture indicated that35CrMo samples of80Hz-loading and20Hz-loading mainly occurred at specimen surface under the full stress amplitude level, GCr15samples of80Hz-loading and20Hz-loading have accured at a surface inclusion or an internal inclusion under the full stress amplitude level, Experimental results show that the ultrasonic loading frequency increased the fatigue life of GCr15and35CrMo steel. It’s inappropriate to research steel material’s giga-cycle fatigue with ultrasonic experiment methods.