Composite model of internal stress field in the steel P91

One of the refined versions of the composite model suggested by Sedlacek et al. is adopted in a modeling of the local stress field in the steel type P 91. The microstructure of the steel is considered as a one-dimensional subs tructure in which the subgrain interiors represent soft regions and subboun daries discontinuously decorated by carbide particles are hard regions. Two limiting structures locally approximating the real substructure, i.e., a s ubstructure with particle-free and a substructure with particle-decorated s ubboundaries, are considered. In the latter case, the model takes into acco unt different elastic moduli of the hard and the soft regions. As an applic ation to experimental data, some predictions for the internal stress and fo r the changes of the stress field due to evolution of microstructure in cre ep are discussed.