1982 Volume 68 Issue 8 Pages 1046-1053
It is well known that microstructural alteration such as a dark etching constituent (D. E. C.) and a white etching constituent (W. E. C.) occurs on the area adjacent to the rolling surface due to rolling contact fatigue. Specimens taken from high carbon chromium bearing steel were fatigue tested in the thrust type rolling fatigue testing machine for these experiments to investigate into microstructural alteration.
The D. E. C., W. E. C. and plate-like carbides were observed among which the plate-like carbides were found out most closely related to the flakings in the specimens for the thrust type tester and observed under approx. 80% of the flakings. Their hardness was up to 1300 of HV. Some plate-like carbides formed perpendicular both to the rolling surface and to a tangent to the rolling track with the plate surfaces and others formed parallel to the rolling surface.
The plate-like carbides formed during fatigue testing had higher carbon concentration than that of the matrix, which indicates a considerable amount of carbon diffused to generate the plate-like carbides during the test.