Surface Durability of Steel Rollers : In Relation to Hardness

抄録

In order to clarify the effects of hardness on the surface durability and surface failure, fatigue tests on various heat-treated steel rollers were carried out under sliding rolling contact condition. The surface failure modes could be estimated by the values of the maximum amplitudes A_max of the ratios of normal stress on the surface in circumferential direction of roller and of orthogonal shear stress under the surface to Vickers hardness and the peak amplitude A_{peak b} of the ratio of orthogonal shear stress to Vickers hardness which occurs at case-core boundary. The relation between the surface durability together with the surface failure mechanism and the hardness distribution could be clarified by calculating the amplitudes A_max and A_{peak b} and by Vickers hardness at the depth of these amplitudes. From the standpoint of design, the surface durability of a machine element can be evaluated from the equation A_max=0.051 or A_{peak b}=0.035 when the hardness and residual stress distributions of the machine element are known.