Stress–Strain Kinetics in Calculations of High-Temperature Strength and Longevity of Reactor Structures

The plastic properties of materials must be used more fully as working temperatures and temperature gradients increase. The results of tests performed on refractory chromium-nickel alloys with combined low-cycle strain with prescribed total amplitudes and strain increments per cycle are presented. The results are compared with those obtained with rigid, cyclic, sign-alternating, and monotonic strain. A method of constructing mathematical models of a material that take account of short- and long-time characteristics of a metal in combination with the possibility of their direct use in readily available packages implementing the finite-elements method is described.