Effect of refined cementite on the microstructure and properties of nanostructured bainitic bearing steel

Abstract The effects of refined cementite of GCr15Si1Mo nanostructured bainitic bearing steel on the microstructures and properties are investigated in this paper. Fine cementite with a mean size of 0.20 μm and a distribution density of 2.46 μm−2 is obtained through the pretreatment process. Compared with the reference specimen, the thickness of bainitic ferrite plate is reduced from 66 nm to 33 nm, and the volume fraction of retained austenite is increased by 8%. The specimen with refined cementite possesses a similar hardness, a lower toughness compared with the reference, but a substantially improved wear resistance due to a single furrow wear mechanism. This research indicates that fine cementite has a complex influence on the microstructures and properties of the bearing steel, which supports the later research of controlling cementite in bearing steel.