INVESTIGATION OF THE KINETICS OF FATIGUE MACROCRACKS UNDER TRANSVERSE SHEAR

摘要

We study the kinetics of shear macrocracks under the conditions of fatigue fracture by transverse shear of thermally hardened 65G steel with a troostite-sorbite structure for low-, middle-, and high-amplitude cyclic loads. We plot the kinetic diagrams of fatigue fracture with regard for the friction of the faces of a shear crack within the range of its growth rates covering up to six orders of magnitude. On the basis of the constructed dependence, we determine the principal and additional characteristics of cyclic crack resistance. We also study the contact interaction of the faces of fatigue cracks and the fractographic features of fracture under the conditions of low-and high-amplitude deformation by cyclic transverse shear.