TY - CONF A1 - Jürgens, Maria A2 - Skrotzki, Birgit A2 - Jürgen, Olbricht T1 - Creep fatigue behavior of P91/P92 T2 - ECCC 2017 N2 - 9-12% Cr ferritic-martensitic stainless steels are widely used as high temperature construction materials in power plants due to their excellent creep resistance and good oxidation resistance. Creep resistance is considered as the primary parameter in material selection for base-load power plants, but the growing share of renewable energy sources in power generation forces many installations into more "flexible" operation with frequent load reductions and shutdowns. Under cyclic operation of power plants, temperature gradients occur especially in thick-walled components. Locally, these gradients lead to complex time- and temperature-dependent loading scenarios which may result in superimposed creep deformation/damage, creep-fatigue and thermo-mechanical fatigue. The combination of different damage processes may seriously reduce the lifetimes of respective components. A fundamental understanding of the damage evolution in ferritic-martensitic steels under combined static and cyclic loading is therefore required. In the present contribution, the creep-fatigue behavior of two different 9% Cr steel grades (P91 and P92) was investigated. Standard creep-tests as well as LCF/TMF tests with hold time have been carried out to study the material behavior of the new loading scenarios. Microstructural investigations help to identify the observed deformation characteristics and the dominating damage mechanisms under different loads. The test programme is complemented by cyclic creep-tests (temperature change) and creep-tests under atmospheres. In a next step, the experimental results will be used for parameter identification of a deformation and lifetime model to predict the material behavior. T2 - ECCC 2017 CY - Düsseldorf, Germany DA - 10.09.2017 KW - Near-service testing KW - Power plant KW - Ferritic-martensitic steels KW - P91 KW - P92 KW - Creep-Fatigue PY - 2017 UR - https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/42270 AN - OPUS4-42270 SN - 978-3-514-00832-8 SP - 1 EP - 5 AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany