Author(s)

H.N. Ko, C. Kagaya, H. Itoga, K. Tokaji & M. Nakajima

Abstract

Effect of fine particle bombarding on fatigue strength of high strength steel H. N. Ko\ C. Kagaya^, H. Itoga', K. Tokaji^ & M. Nakajima ^ Nakanihon Automotive College, Japan. ^Department of Mechanical Engineering, Chubu University, Japan. *Department of Mechanical and System Engineering, Gifu University, Japan Department of Mechanical Engineering, Toyota National College of Technology, Japan. Abstract The cantilever-type rotary bending fatigue test was performed at room temperature on high carbon chromium steel. Three kinds of specimens were prepared for comparison, i.e. fine particle bombarded, shot peened and untreated. Each specimen showed a step-wise S-N curve which had a transition stress, transferring the fatigue fracture initiation from surface to subsurface with decreasing the applied stress. The effect of the surface treatment appeared at stress levels above the transition stress of untreated specimen, while it disappeared at stress levels below that stress.

Keywords