Crystallographic preferred orientation induced by cyclic rolling contact loading

Fine focus X-ray diffraction methods have been applied to analyze the texture development of the ferrite phase during rolling contact fatigue of 6309 type deep groove ball bearing inner rings prepared from hardened and tempered SAE 52100 steel. Textures of the ferrite matrix as {100}〈110〉 and {111}〈211〉 (where {hkl} denotes the crystallographic plane that is preferably parallel with the contact surface and 〈uvw〉 denotes the crystallographic direction that is preferably parallel with and in the direction of over-rolling) have been identified in a small region below the rolling contact surface. These textures develop gradually with an increasing number of stress cycles and become noticeable in conjunction with changes in residual stress, microstrain, and volume fraction of retained austenite in the same region. Upon rolling contact loading, both textures can become very pronounced, while the shape of the subsurface volume, where plastic deformation takes place in particular, remains unchanged: material displacement in the subsurface volume is less than 5 µm in the three principal directions. Crack propagation in association with spalling fatigue failure has been shown to be related to the type of texture developed.