Hot-deformation characteristics of Waspaloy

Abstract

Specimens of wrought Waspaloy have been reheated to above the γ' solvus temperature and tested in plane-strain compression at constant equivalent tensile strain rates in the range 0.5–50 s⁻¹, and at initial test temperatures in the range 960–1070°C. The majority of tests were conducted with the tools and test environment at 850°C. Dynamic recrystallization was observed under all test conditions, but was only complete by the strain limit of 2·7 in tests at the highest temperatures. Static (metadynamic) recrystallization initiated rapidly after deformation. Flow stress, either at the peak or at a constant strain, is related exponentially to strain rate, and gives an activation energy of 475 kJ mol⁻¹ when related to the instantaneous temperature, which changed rapidly during deformation. For practical purposes, the stress-strain-strain-rate-temperature relationships may be treated as equations of state.

MST/96