Abstract
Effect of metallographical factors on the rolling fatigue life of 1%C-1.5%Cr bearing steel was investigated, and the most profitable component for the bearing life was discussed.
The results obtained are as follows:
(1) Metallographical factors affected on the rolling fatigue life of bearing steel were not amount and size of residual cementite but the chemical compositions soluted in fhe matrix.
(2) The most effective factor affected on the rolling fatigue life was carbon content soluted in the matrix and the most desirable carbon content in the matrix was about 0.5 percent.
(3) It was recognized that the mechanism of flaking was related to the third stage of the tempering of martensite. This was deduced from the observation of the micro-structure of cyclic stressed area by the transmission electron microscopy and the result of bearing life test of a new type steel with higher silicon of which the starting temperature of the third stage was rised by silicon.
