Residual stresses in induction-hardened gear teeth mapped by neutron diffraction

摘要

Surface-hardening treatments are used in order to enhance the resistance of mating gear teeth surfaces to wear and fatigue crack initiation. The treatments create a compressive residual stress state near the tooth surface, which acts to impede crack initiation and propagation. Accurate determination of this residual stress field is important for quantifying the effect of treatment and optimizing the processing conditions. Neutron diffraction provides a powerful non-destructive experimental tool for residual stress evaluation. By collecting residual strain data for three different orientations, the principal stress directions and values can be mapped. This paper describes the procedure used for building such maps using the G5.2 spectrometer at Laboratoire Leon Brillouin, Saclay, and presents the results obtained for an induction-hardened gear.