Procedure for Nondestructive Rs-measurements of Inner Surfaces of Ball Bearing Components

Machining induced residual stress states contribute to the distortion of machined components during heat treatments. Thus, ideally a complete characterization of the components residual stress state is required. Magnetic and micromagnetic analysis of residual stresses can represent an important gain of time if compared to X-ray diffraction. Another important advantage is the access of inner faces of components like ball bearing rings. This study presents a comparison of these two methods for the characterization of outer and inner surfaces of ball bearing rings. A good calibration of micromagnetic measurements with X-ray diffraction data is necessary. Reliable results then can be achieved and the residual stress states of rings can be characterized. Effects of clamping systems and feed on the residual stress levels and distribution will be discussed, as well as complex interactions. An implementation of the presented micromagnetic method for non-destructive control in large manufacturing series could be possible.