Solute redistribution in the nanocrystalline structure formed in bearing steels

The microstructural alteration in a white etching area (WEA) formed during rolling contact fatigue of a 1C–1.8Cr steel (wt.%) is studied. A uniform nanocrystalline structure with scattered carbide particles is observed. Si and C atoms segregate to different regions in the cell boundaries, implying a repelling behaviour. Carbon-rich clusters were identified but contained less than 25 at.%C. It is suggested that the interaction between Si and C should be considered in the mechanism for microstructural decay.