Special features of the deformation kinetics of structural materials in cyclic elastoplastic deformation

Abstract

1. The results show that the elasticity modulus of the VT3-1, KhN73MBTYuVD, and KhN77TYuRVD alloys greatly varies (by up to 40%) during cyclic loading. This fact must be taken into account in evaluating the stress state of components and predicting their life. 2. The existence of the recovery effect in the material after removing the load indicates that the evaluation of the degree of damage of the material of the component in service by verifying its mechanical properties in single-cycle loading is ineffectively. 3. VT3-1 titanium alloy is acceptable to softening in the symmetric load cycle even if the amplitude of the acting stresses is considerably lower than the proportionality limit. 4. The mechanism of cumulation of residual plastic strains in the nickel-based alloys and titanium alloys greatly differs depending on the nature of load variation: in the symmetric load cycle the nickel alloys are characterized by one-side cumulation of residual strain ɛr which is not detected in VT3-1 alloy; on the other hand, for the nonzero cycle cumulation of ɛr was detected only in the titanium alloy.