Abstract
A theory of steady-state creep is here presented, based on the rate of climbing of piled-up dislocations and the fraction of Frank-Read sources working at a given stress. Grain boundaries are considered as the source to produce equilibrium concentration of vacancies. The theory gives a linear relation between log(ε/σ2) and L/σ, where ε and σ are the creep rate and the applied stress respectively. The experimental creep data with several metals gave a fairly good fitting to the relation. And, from the slope of the plotting the average length of Frank-Read sources can be calculated. It is about 2.1, 1.8 and 0.26 microns for annealed polycrystalline specimens of Cu, Al and an 18-8 stainless steel, respectively.
