Fatigue behavior of carburized steel with internal oxides and nonmartensitic microstructure near the surface

The characteristic fatigue behavior of carburized and quenched steel with internal oxides and non-martensitic microstructure near the surface was presented through rotating bending fatigue test. The S-N diagram revealed two knees and the specimens continued to fail over 10⁷ stress cycles. The fatigue limit could not be obtained even at 10⁸ stress cycles. The test results were compared to those for the specimens without surface structure anomalies to show the effect of structure anomalies on the fatigue behavior of carburized steel.