Fast and versatile measurement of residual stress and hardness of gear and shaft materials - Finding material defect change of residual strain by gear operation

摘要

Using X-ray diffraction apparatus of Cos α principle, gear material is observed: the measured FWHM value shows very good agreement with Vickers' hardness value. When the steel texture is not normal due to e.g. inadequate hardening process, this FWHM vs. Hardness correspondence becomes poor. At the limiting position of tooth contact on dedendum flank of gears, where two times of tooth contact, i.e. tip edge contact and flank-to-flank contact, occurs, the measured value of FWHM decreases just in the same figure of surface temperature distribution. This suggests that the load carrying capability of surface material changes as function of induced surface temperature during heavy operation of gears.