Influence of Inclusions on the Fatigue Strength of Shot Peened Carburized Steel

Author:  Toyoda, Kanazawa, Hisamatsu, Ishiguro
Source:  Conf Proc: ICSP-5, (p.333-340)
Doc ID:  1993084
Year of Publication:  1993
Abstract:  
Shot peening method is widely applied to gas carburized gears for automobile to improve the fatigue strength. When the strength is improved by shot peening, the fractue origins tend to shift from the surface toward the inside. In the case of inside fracture, cracks often originate from non-metallic inclusions existing in the steels. The purpose here is to investigate the influence of inclusions on the fatigue strength of shot peened carburized steels. The fatigue strength values were obtained by rotating bending fatigue tests using two kinds of steels which have different oxygen contents. When high arc-height shot peening was treated, the low oxygen contents steel, which contained less inclusions, exhibited higher strength than that of conventional steel.