The Effect of Rolling Temperature on the Microstructure and Mechanical Properties of Surface-Densified Powder Metallurgy Fe-Based Gears Prepared by the Surface Rolling Process

In this investigation, the surface-rolling process was performed to improve the performance of PM (powder metallurgy) parts. Different rolling temperatures were applied and the effect of rolling temperature on the microstructure and mechanical properties of the surface dense layers in the samples were investigated. In the study, room temperature and temperatures of 100 °C, 200 °C, 300 °C were studied during the rolling process. The results confirmed that the sample prepared with a pre-heated temperature of 200 °C had the lowest porosity at the surface area. It also exhibited the highest surface hardness and wear resistance. The optimum rolling temperature was determined to be 200 °C and the related mechanism was discussed.