Fatigue Behavior and Short Crack Growth in Ferritic-pearlitic-bainitic Steel

Abstract

Fatigue behavior of ferritic-pearlitic-bainitic steel, in particular the initiation and short crack growth has been studied. Smooth cylindrical specimens and cylindrical specimens having a shallow notch were produced from a massive forging. Fatigue cracks initiate preferably in persistent slip markings in areas of proeutectoid ferrite. Fatigue cracks grow with a contribution of crack linkage. The kinetics of short crack growth has been described using the concept of an “equivalent crackâ€. The plastic strain amplitude plays a dominant role in crack initiation stage, in the growth of short cracks and in the fatigue life evaluation.