FATIGUE BEHAVIOR AND SHORT CRACK GROWTH IN FERRITIC-PEARLITIC-BAINITIC STEEL

摘要

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