Application of a physically-based dislocation creep model to P92 for constructing TTR diagrams

Description

To raise the efficiency of thermal power plants, operation temperature and pressure must be increased. This can be achieved by higher creep resistance and longer creep life of materials such as martensitic Cr-steels. To understand the underlying mechanisms of degradation, physical creep modelling provides a detailed and profound insight into microstructural processes. For such a physically-based dislocation creep model it is demonstrated that on basis of a parameter set found for one experimental creep curve, numerous creep curves on different stress levels can be simulated without any additional experimental data. These simulation results are then used for constructing a complete TTR diagram for a 9% Cr-steel. Our approach is not only able to extrapolate rupture times for different applied stresses, but also for different temperatures. In all cases, microstructural evolution of the simulated material is considered including dislocation density, subgrain size and precipitates. The obtained rupture times in the simulated TTR diagram are compared to reference data, achieving good agreement.

Period	20 Oct 2021
Event title	5th International ECCC Creep & Fracture Conference
Event type	Conference
Degree of Recognition	International