Technique for low-cyclic fatigue tests under isothermal and nonisothermal conditions of hard loading

Test results for low-cycle fatigue of 12Kh18N10T and 2Kh13 steels under isotthermal and nonisothermal conditions of hard loading are presented. The samples have been subjected to hard elastic-plastic deformation with the constant rate of mechanical deformation. At that, under conditions of nonisothermal loading the temperature changed in a cyclically synchronous way with mechanical loading so, that the maximum temperature of the cycle corresponded to the maximum deformation during extension. It is shown that to evaluate the damage it is necessary to take into account the level of temperature, the hold time, and structural transformations, affecting the mechanical properties of the materials