In order to elucidate the influences of the variation of eutectic carbide content and the distribution of matrix on the rolling contact fatigue strength of alloy white cast iron, an experimental study was conducted by using an Amslar-type wear testing machine under sliding conditions with light oil as a lubricant.
The results obtained are summarized as follows:
(1) The rolling contact fatigue endurance limit of alloy white cast iron was lower than that of bearing steel (SUJ2) having the same microstructure of matrix of the alloy white cast iron. The tendency became more pronounced with increasing amount of eutectic carbide.
(2) The rolling contact fatigue endurance limit of alloy white cast iron was improved by forging.
(3) The rolling contact fatigue endurance limit of the alloy white cast iron increased with matrix hardness.
(4) A crack propagated along the boundary of eutectic carbide and matrix structure, and after that it penetrated into the vicinity of the region at which the stress value calculated according to the shearing stress amplitude maximum theory reached the maximum, and then the crack propagation went in the parallel direction with the contact surface.