抄録
In this study, the authors have investigated and clarified that ion nitriding was able to improve the fatigue properties of tool steel. Three kinds of specimens under the different heat treatment conditions were used in this study. The fatigue test had been performed using a rotating bending fatigue testing machine to investigate the effects of ion nitriding on fatigue properties of tool steel. The fatigue fracture surface was analyzed using a scanning electron microscope (SEM), and hardness distribution was also investigated using a microhardness tester. The fatigue strength and hardness of the heat treated specimen were much greater than those of the non-heat treated specimen. It is considered that the micro structure of the heat treated specimens was refined; and the refined structure reduced fatigue failure and increased hardness of the specimens. According to the results of the fatigue test, the most effective treatment method on improving the fatigue limit was determined in this study. The hardness of the specimens remarkably increased after ion nitriding processing.
