Abstract
In the extremely low cycle fatigue, a transition of the fracture mode occurs from the surface to internal fracture with an increase in the plastic strain range. Such a transition is caused by an increase in the paerlite cracking inside the material. The pearlite cracking is greatly dependent on the own direction of lamellael in a pearlite grain. Work Hardening and paearlite grain turning under cyclic plastic strain affects an increase in the paearlite cracking.