Mechanisms and kinetics of the early fatigue damage in crystalline materials

The localization of the cyclic plastic strain and its effect on the hysteresis loop, on the surface relief evolution and on the internal dislocation structure of austenitic and ferritic stainless steels are presented. Extrusion and intrusion formation is studied using atomicforce microscopy. The experimental findings concerning the surface relief formation and crack evolution are confronted with existing models of fatigue-crack initiation. Short crack growth kinetics is documented and the short crack growth law and its parameters are compared with the Coffin–Manson law.