Department of Structural Materials
We investigate the behavior of materials exposed to energetic particle irradiation. The work contributes to the program NUSAFE (Nuclear Waste Management, Safety and Radiation Research) of the Helmholtz Association.
Neutron irradiation provokes the formation and long-term evolution of nm-scale defects such as dislocation loops and solute atom clusters. These defects give rise to hardening accompanied by a reduced fracture resistance of reactor pressure vessel steels of running nuclear power plants. Materials for advanced reactor concepts will be exposed to higher operation temperatures and higher neutron doses. The overall objectives of our research are to identify the mechanisms of irradiation-induced damage in structural materials and to assess the resulting changes of the mechanical properties.
We work on two main directions:
- In the case of running nuclear power plants, the work is focused on long-term irradiation effects in reactor pressure vessel steels.
- Our work in the field of advanced reactor concepts is dedicated to ferritic/martensitic Cr-steels, oxide dispersion strengthened (ODS) steels and the emerging class of high-entropy alloys.
The new insight substantially contributes to the scientific background for the safety assessment of nuclear reactors. The work is embedded in the Euratom projects SOTERIA, MATISSE and M4F. A close cooperation with the Fundamentals and Simulation Group provides additional insight via atomistic simulation.
- Mechanical testing of irradiated materials
- Characterization at the nm length scale
- Ion irradiation to emulate neutron irradiation effects
The effect of composition and microstructure on the creep behaviour of 14 Cr ODS steels consolidated by SPS
Meza, A.; Macía, E.; Chekhonin, P.; Altstadt, E.; Rabanal, M. E.; Torralba, J. M.; Campos, M.
There is a general need for alternative structural materials to improve power plants' efficiency and reduce CO2 emissions. Within this framework, two new compositions of temperature-resistant sintered ODS ferritic steels (14Cr-5Al-3W), strengthened by a fine dispersion of precipitates (5·1022 ox. /m3), have been developed. This work focuses on creep properties and microstructure evolution. The creep resistance (at 650°C) could be improved by prior microstructural optimisation, thanks to the consolidation by spark plasma sintering and the tailoring of precipitates' nature when a single compound introduces the oxide-forming elements (Y-Ti-Zr-O) synthesised for this purpose. To this end, the initial pre-alloyed ferritic powder was mechanically alloyed with the synthesised compound and sintered by spark plasma sintering (SPS). Afterwards, EBSD and TEM characterisation were employed to study the microstructures. Small punch creep tests (SPCT) were performed on the steels to analyse their creep performance. These showed an exceptional enhancement of the creep resistance in the steels containing the Y-Ti-Zr-O additions.
Keywords: 14Cr-ODS steel; fine grain; creep behaviour; SPCT
Materials Science and Engineering A 849(2022), 143441
- Secondary publication expected from 27.06.2023
|Name||Bld./Office||+49 351 260|
|Dr. Eberhard Altstadt||801/P151||2276||e.altstadthzdr.de|
|Dr. Cornelia Kaden||801/P102firstname.lastname@example.org, c.heintzehzdr.de|
|Name||Bld./Office||+49 351 260|
|Dr. Frank Bergner||801/P150||3186||f.bergnerhzdr.de|
|Dr. Paul Chekhonin||801/P146||2149||p.chekhoninhzdr.de|
|Dr. Andreas Ulbricht||801/P146||3155||a.ulbrichthzdr.de|