Fatigue properties of cold-rolled notched eutectoid steel

This paper presents the results of a research on the effect of cold rolling on fatigue properties of notched eutectoid steel. The results indicate that the fatigue strength of the material is improved significantly following cold rolling. Non-propagating cracks are found on the surfaces of all four cold-rolled specimens used in the test and the depths of the cracks increase with the increasing of the degree of plastic deformation. Compressive residual stresses, work hardening and fiberized microstructure are the three main factors responsible for the modification of fatigue properties. Compressive residual stresses can effectively improve the resistance to fatigue crack propagation into the interior region of the specimens. The fundamental mechanisms for fatigue strength improvement are also discussed.