| Popis: |
Fatigue tests carried out at Centre Technique des Industries Mecaniques (CETIM) on a NF 42CD4 grade steel (G 41420) show that grinding parameters such as down feed and the type of wheel have a very clear influence on residual stresses and fatigue limit under plane bending. The stability in fatigue of residual stresses obtained by three grinding conditions were evaluated, using X-ray diffraction methods, in order to introduce values of the stabilized residual stresses into a calculation procedure developed for determining fatigue strength. This analysis contributes to a better knowledge of grinding effects in fatigue and allows the distinction between the respective influence of surface roughness and residual stresses. This project also demonstrates the importance of the reduction of the tensile residual stresses during fatigue, and the relationship between this reduction and the behavior of the metal under cyclic loading. |
