Abstract
A theoretical treatment is given of high-temperature stress relaxation and stress-transient dip testing using a mixed elastic-anelastic modulus. Formulae are derived to describe the relative relaxed stress level as a function of the prior applied strain rate. The theory is shown to be valid for all the existing data in the literature. A particular experimental study has been made at 530°C on copper and dispersion-hardened copper and the results confirm the detailed predictions of the model. A brief discussion is given of the origin of the widely-observed transient effects and it is shown that the contribution of dislocation bowing and grain boundary relaxation is far more significant than previously supposed.