Abstract
In order to clarify the effects of the defect on the fatigue properties of thermally sprayed steel with special focus on the defect size, rotating bending fatigue tests and measurements of the defect size were performed of specimens with the long heating period and short one in the fusing process by using a vacuum furnace. The fatigue strength and the defect size of long heating period specimens were lower and smaller than that of short one. Additionally with the long heating period specimens, rotating bending fatigue tests and measurements of the defect size were carried out about three types of coating thickness. The defect size strongly affects the fatigue properties; the thinner the coating, the smaller the defect size and the higher the fatigue strength. It can be considered that the defect size in coating is one of the most important factors which affect the fatigue properties of the thermally sprayed steel.
