Abstract
As one of the effective and low cost surface modification, the authors have been studying and clarified roller working to be able to improve the fatigue properties of bar shape components. In this study, fatigue test is performed to research the influence of roller working on fatigue properties and determine optimum value by roller working using eutectoid steel. Six kinds of specimens (the deformation value are 0, 0.05, 0.1, 0.15, 0.25 and 0.3mm, respectively) are used for this study by keeping the same final shape and dimensions. According to the results of fatigue test, the compressive residual stress generated in the roller working is one of the main factors for the improvement of fatigue strength, and the fatigue limit does not necessarily increase with the increase of deformation values. There exists an optimum value by roller working for improving the fatigue strength. The reasons why the fatigue limits change with the variation in plastic deformation values and why there exists an optimum deformation value are examined by analyzing residual stress, the variation in micro structure and Vickers hardness distribution.
