Improvement of the Rolling Contact Fatigue Strength of Sintered Steel for Transmission Component 890412
A sintered steel with a high rolling contact fatigue strength of 1660 MPa was developed using a new process and modified powder. It is expected to be used for heavy duty gears and races for automatic transmissions.
The process consists of compacting, sintering, repressing and a deep carburization. It is a more simple process than the conventional one like hot powder forging and the repress-resintering process. The repressing is used to get a density of 7.4 g/cm3 and above. Another of its merit is a better dimensional tolerance and economic efficiency. Deep carburization is used to obtain a very hard surface layer and good mechanical properties by means of resintering pores upset by repressing.
Some process parameters and chemical composition are to be discussed in terms of the rolling contact fatigue strength compared to wrought steels.
Citation: Itoh, Y., Motooka, N., Takeda, Y., and Kureha, Y., "Improvement of the Rolling Contact Fatigue Strength of Sintered Steel for Transmission Component," SAE Technical Paper 890412, 1989, https://doi.org/10.4271/890412. Download Citation