油中における疲労挙動と油粘度の関係 : S35C平滑材の回転曲げ

抄録

Using a series of base oils of different viscosity grades, rotating bending fatigue tests of 0.34 % C steel plain specimens were carried out to examine the effect of oil environments on the fatigue behavior. Although the effect of oil is hardly observed in one grain size crack initiation process, its effect appears in the crack propagation process. As the main effects of oil, two actions are considered ; that is, the isolation of the atmosphere and the oil wedging action. The propagation of a crack smaller than 0.1mm is controlled mainly by the former effect. For a crack larger than 0.1mm, its behavior is controlled mainly by the latter effect. On the other hand, the effect of oil on the fatigue limit is very small.