Determining activation volumes for thermally activated dislocation glide in creep-resistant martensitic Cr-steels
Sprache des Vortragstitels:
Englisch
Original Tagungtitel:
THERMEC'2023 - International Conference on PROCESSING & MANUFACTURING OF ADVANCED MATERIALS, Processing, Fabrication, Properties, Applications
Sprache des Tagungstitel:
Englisch
Original Kurzfassung:
Dislocation glide plays an essential role for the propagation of creep in environments exposed to high stresses and temperatures, such as in thermal power plants. One of the important ingredients for calculating the glide velocity is the activation volume. In this work, different concepts are discussed on how to determine activation volumes for martensitic Cr-steel P91. One method is deducing activation volumes from stress relaxation data. Another approach is to estimate activation volumes from time-to-rupture data. In this work, stress relaxation data recorded by a deformation dilatometer and time-to-rupture data from creep tests are evaluated. The findings are compared and an optimized strategy for the determination of activation volumes is presented. The result can be used for calculating creep curves based on a recently published dislocation creep model.