Oxide dispersion strengthened (ODS) steels are considered to be promising candidates for the blanket material in fusion reactors and fuel cladding tubes in GEN IV fission rectors. These steels are currently under investigation in comprehensive research programs worldwide. For the application, the behavior of ODS steels under distinct loading conditions is of decisive importance.
Within the frame work of European project MATISSE (Materials' Innovations for a Safe and Sustainable nuclear in Europe, http://www.fp7-matisse.eu/), a project dealing with materials for transmutation technologies and advanced reactors, the complex deformation and damage behavior of 9Cr-ODS (tempered martensitic state) and 12Cr-ODS (ferritic state) steels are under investigation. Due to limited availability of the materials the investigation shall be performed on miniaturized specimens.
Preliminary uniaxial tensile tests at room temperature and application relevant temperatures up to 800°C have already been performed. A systematic investigation of the deformation and damage behavior of both ODS steels under cyclic loading is under progress. The focus is set on the influences of the temperature, loading amplitude and loading rate on the behavior and development of the microstructure within the course of cyclic loading. The test shall be accompanied by microstructural investigations at different scales for the identification of the main deformation and damage mechanism. Based on the knowledge collected suitable constitutive equations for deformation and damage shall be selected from the literature and if necessary developed further to describe the observed behavior.