Low-Cycle Fatigue of a VZh175 Nickel Superalloy during Asymmetric Loading

Abstract

The results of low-cycle fatigue (LCF) tests of a VZh175 nickel superalloy are presented. LCF is one of the main strength characteristics of nickel superalloys subjected to cyclic loading. The LCF tests are carried out during symmetric and asymmetric loading at room and high temperatures. The experimental results are presented in the form of regression lines related the logarithm of stresses and the logarithms of the number of cycles to failure and the number of cycles corresponding to 50% failure probability and in the form of tables. A change in the testing conditions, i.e., asymmetric loading and high test temperatures, is found to decrease the LCF alternating stress amplitude significantly. As compared to an increase in the test temperature, an increase in stress ratio R more strongly affects the decrease in the alternating stress amplitude σ_a in the ranges of these parameters under study.