Interpretation of high-temperature creep of type 304 stainless steel

Abstract

The elevated-temperature creep behavior of Type 304 stainless steel is examined in terms of the measured effective and internal stresses. Results show that the mean effective stress is related to the applied stress by a power law of the form σ^* = α(σ)^β, where the constants α and β are functions of temperature. The dependence of creep rate on applied stress follows a power law, and the stress exponent is dependent on temperature. The latter behavior arises from the variation in the mean effective stress with applied stress and temperature. The creep rates are also described as a function of effective stress. The dislocation velocity-stress exponent obtained from stresschange tests is higher than the effective stress exponent evaluated from creep data. The dependence of creep rate on temperature at various values of effective stress yields a total activation energy of approximately the same magnitude as self-diffusion.