On the Choice of Forming Modes and Estimation of Residual Service Life Using Kinetic Equations with a Scalar Damage Parameter

The kinetic equations of creep are used to compare damage accumulation in rods under tension in two forming modes: at constant stresses and at constant strain rates corresponding to strain rates in steady-state creep for the same stresses. It is found that from the point of view of increasing the residual service life at the production stage, forming to the required strain value with specified kinematics is preferable to forming at constant stresses for materials on whose strain-time diagrams for σ = const, the fracture strain decreases monotonically with increasing stress. Forming at constant stresses is preferable for materials on whose strain-time diagrams for σ = const, the fracture strain increases monotonically with increasing stress. Calculation results for several alloys are presented.