Rolling Contact Fatigue Tests of Selectively Densified Materials

Selectively densified rollers from Distaloy DC-1, Astaloy Mo and Distaloy AE have been rolling contact fatigue (RCF) tested on a ZF-test rig. The rolling contact fatigue endurance limit of the Astaloy Mo based material is approximately 1500 MPa that can be compared to the selected reference material, AISI 5115 (DIN 16MnCr5), 1600 MPa. For the diffusion-alloyed materials, Distaloy DC1 and Distaloy AE, it was not possible to determine the endurance limit due to too few tests. However, the endurance limit seems to be slightly lower than the Astaloy Mo material. The case depth seems to be low for all materials, but the effect appears to be more severe for the Distaloy DC1 material. Surface cracks of different character could be found in all specimens. Small cracks associated with smaller pits are found on the run outs (>50·10⁶ cycles).