The microstructural interpretation of internal stresses measured in high-temperature creep by using the strain-transient dip-test technique was considered. The development of microstructure in the course of creep was considered a transition from uniformly distributed dislocations to a well-developed substructure. The substructure was supposed to have a composite character that consisted of cell or sub-grain boundaries with few dislocations in cell or sub-grain interiors. Model equations for the relation of internal stress to the parameters of the dislocation structure were discussed and examined with reference to experimental data. The evolution of internal stress in creep. evaluated using different formulae. was compared with the evolution of macroscopically measured internal stress. The use of applied-stress dependences of microstructure parameters permits quite realistic estimates of the values of internal stress in steady-state creep.

Internal Stress and Heterogeneous Dislocation Structure in Creep. A.Orlová, F.Dobeš: Philosophical Magazine, 2003, 83[23], 2681-91