Microstructures and properties of a novel carburizing nanobainitic bearing steel

Nanobainite and dispersed carbides were gained on the surface layer of a modified carburizing 23Cr2Ni2SilMo bainitic bearing steel based on carburization, tempering at high temperature, and succedent low-temperature isothermal quenching. As compared with the conventional carburizing 20Cr2Ni4 martensitic bearing steel, the novel carburizing 23Cr2Ni2Si1Mo nanobainitic bearing steel showed a much higher wear-resisting performance and rolling contact fatigue performance. Moreover, the hardenability and the comprehensive mechanical property of the modified 23Cr2Ni2SilMo bearing steel are better than those of the 20Cr2Ni4 bearing steel. The excellent properties suggest that the novel carburizing 23Cr2Ni2SilMo nanostructured bainitic steel is very promising to manufacture heavy-duty bearing, especially for bearings that bear impact load and need high wearresisting performance and high rolling contact fatigue performance during their service life.