Influence of hard turned roller bearings surface on surface integrity after deep rolling

The endurance of highly loaded parts such as bearings is influenced by their surface integrity. Low surface roughness and high compressive residual stresses lead to an increased lifetime. In contrast to grinding and honing, the processes hard turning and deep rolling can induce compressive residual stresses up to1000 MPa with depths of d0 = 500 μm in combination with surface roughness values of Rz < 0.8 μm. Combining both processes to the innovative hybrid turn-rolling exhibits benefits with respect to topography and residual stress stability. Developing this process, the interactions of the single processes are analyzed in this paper.