Structural Materials
The safety of nuclear reactors critically depends on the mechanical behavior of structural materials under harsh environmental conditions (neutron irradiation, high temperatures). In the framework of the program NUSAFE (Nuclear Waste Management, Safety and Radiation Research) of the Helmholtz Association we characterize irradiated reactor materials from the nm-scale to the macro-scale. Our focus:
- Long-term irradiation effects in reactor pressure vessel steels of running and new-build reactors in the context of lifetime extension
- Assessment of the irradiation tolerance of innovative materials for future reactor concepts including nuclear fusion (e.g. ferritic/martensitic Cr-steels, oxide dispersion strengthened (ODS) steels, the emerging class of high-entropy alloys)
The methodical spectrum covers the full functional chain from nm-scale irradiation-induced defects to macroscopic mechanical properties and aims at the identification, better understanding and mitigation of irradiation effects. The new insight substantially contributes to the scientific background for the safety assessment of nuclear reactors. The research relies on a unique infrastructure including the hot cell labs for the investigation of neutron-irradiated materials as well as the HZDR Ion Beam Center for ion irradiation experiments.
Our expertise:
- Mechanical testing of irradiated materials
- Nano-/Microstructure characterization of irradiated materials
- Ion irradiation to emulate neutron irradiation effects
Current projects
- Innovative structural materials for fission and fusion
(INNUMAT, EU, HORIZON-EURATOM, 2022-2026) - European Database for Multiscale Modelling of Radiation Damage
(ENTENTE, EU-H2020-Euratom, 2020-2024) - Fracture mechanics testing of irradiated RPV steels by means of sub-sized specimens
(FRACTESUS, EU-H2020-Euratom, 2020-2024) - Structural Materials research for safe Long Term Operation of LWR NPPs
(STRUMAT-LTO, EU-H2020-Euratom, 2020-2024) - Untersuchungen zum Ausheilverhalten von Reaktordruckbehälterstählen bei niedrigen Temperaturen
(WetAnnealing, BMWI, 2020-2025) - Physical modelling and modelling-oriented experiments for structural materials 2
(IOANIS2, EERA-JPNM Pilote Project, 2023 - 2027, coordinator HZDR) - In-situ experiments for nuclear applications
(INSITEX, EERA-JPNM Pilote Project, 2023 - 2027) - On the use of small punch as high-throughput screening technique to extract mechanical properties of ion irradiated materials
(SHERPA, EERA-JPNM Pilote Project, 2023 - 2027)
Latest Publication
Assessment of Ni and Mn effect on the irradiation hardening behavior of VVER-1000 model steels exposed to high fluences in the high flux reactor
Pereira, V. S. M.; Radiguet, B.; Onorbe, E.; Ulbricht, A.; Sharma, D.; Etienne, A.; Laot, M. A. L.; Szavai, S.; Martin, O.; Kolluri, M.
Abstract
In the present work, we aim at providing more data and insight related to the influence of Ni and Mn contents on the degree of irradiation hardening of Light Water Reactor RPV steels. A total of 20 model steels and realistic welds based on VVER-1000 and PWR RPVs compositions were irradiated at high flux and to high fluences in the LYRA-10 experiment, conducted in the High Flux Reactor, Petten. Among them, eight VVER-1000 model steels with 0.1 wt % Cu and systematically varied Mn and Ni contents were submitted to tensile and Vickers hardness testing for evaluation of their degree of hardening, and were characterized in detail, using Atom Probe Tomography, Transmission Electron Microscopy, Small Angle Neutron Scattering and Positron Annihilation Spectroscopy. The mechanical testing results show the clear increase in degree of irradiation hardening with the Mn and Ni contents, in particular for steels containing 1.4 wt % Mn. Microstructural observations show direct correlation between increase in yield strength and the formation of Mn-Ni-Si solute clusters. Calculations done
using classic and multiscale models confirm that the solute clusters are the main hardening features present in
the irradiated RPV model steels. Furthermore, TEM and PAS results suggest that dislocation loops have a more
significant role on the formation of solute clusters than on irradiation hardening of the group of materials
investigated.
Keywords: Ni-Mn synergy; Radiation-induced solute clusters; Dislocation loops; Irradiation hardening
-
Journal of Nuclear Materials 615(2025), 155932
DOI: 10.1016/j.jnucmat.2025.155932
Permalink: https://www.hzdr.de/publications/Publ-41414
Team
Head | |||||
Name | Bld./Office | +49 351 260 | |||
---|---|---|---|---|---|
Dr. Eberhard Altstadt | 801/P151 | 2276 | e.altstadt![]() | ||
Dr. Cornelia Kaden | 801/P102 | 3431 | c.kaden@hzdr.de, c.heintze![]() | ||
Employees | |||||
Name | Bld./Office | +49 351 260 | |||
Dr. Frank Bergner | 801/P150 | 3186 | f.bergner![]() | ||
Dr. Paul Chekhonin | 801/P146 | 2149 | p.chekhonin![]() | ||
Vanessa Dykas | 801/P105 | 3363 | v.dykas![]() | ||
Mario Houska | 801/P148 | 2242 | m.houska![]() | ||
Jens Pietzsch | 801/P032 | 2814 3550 | jens.pietzsch![]() | ||
Dr. Andreas Ulbricht | 801/P146 | 3155 | a.ulbricht![]() | ||
Tilo Welz | 801/P032 | 2814 | t.welz![]() |
Latest publication
Assessment of Ni and Mn effect on the irradiation hardening behavior of VVER-1000 model steels exposed to high fluences in the high flux reactor
Pereira, V. S. M.; Radiguet, B.; Onorbe, E.; Ulbricht, A.; Sharma, D.; Etienne, A.; Laot, M. A. L.; Szavai, S.; Martin, O.; Kolluri, M.
Abstract
In the present work, we aim at providing more data and insight related to the influence of Ni and Mn contents on the degree of irradiation hardening of Light Water Reactor RPV steels. A total of 20 model steels and realistic welds based on VVER-1000 and PWR RPVs compositions were irradiated at high flux and to high fluences in the LYRA-10 experiment, conducted in the High Flux Reactor, Petten. Among them, eight VVER-1000 model steels with 0.1 wt % Cu and systematically varied Mn and Ni contents were submitted to tensile and Vickers hardness testing for evaluation of their degree of hardening, and were characterized in detail, using Atom Probe Tomography, Transmission Electron Microscopy, Small Angle Neutron Scattering and Positron Annihilation Spectroscopy. The mechanical testing results show the clear increase in degree of irradiation hardening with the Mn and Ni contents, in particular for steels containing 1.4 wt % Mn. Microstructural observations show direct correlation between increase in yield strength and the formation of Mn-Ni-Si solute clusters. Calculations done
using classic and multiscale models confirm that the solute clusters are the main hardening features present in
the irradiated RPV model steels. Furthermore, TEM and PAS results suggest that dislocation loops have a more
significant role on the formation of solute clusters than on irradiation hardening of the group of materials
investigated.
Keywords: Ni-Mn synergy; Radiation-induced solute clusters; Dislocation loops; Irradiation hardening
-
Journal of Nuclear Materials 615(2025), 155932
DOI: 10.1016/j.jnucmat.2025.155932
Permalink: https://www.hzdr.de/publications/Publ-41414
Team
Head | |||||
Name | Bld./Office | +49 351 260 | |||
---|---|---|---|---|---|
Dr. Eberhard Altstadt | 801/P151 | 2276 | e.altstadt![]() | ||
Dr. Cornelia Kaden | 801/P102 | 3431 | c.kaden@hzdr.de, c.heintze![]() | ||
Employees | |||||
Name | Bld./Office | +49 351 260 | |||
Dr. Frank Bergner | 801/P150 | 3186 | f.bergner![]() | ||
Dr. Paul Chekhonin | 801/P146 | 2149 | p.chekhonin![]() | ||
Vanessa Dykas | 801/P105 | 3363 | v.dykas![]() | ||
Mario Houska | 801/P148 | 2242 | m.houska![]() | ||
Jens Pietzsch | 801/P032 | 2814 3550 | jens.pietzsch![]() | ||
Dr. Andreas Ulbricht | 801/P146 | 3155 | a.ulbricht![]() | ||
Tilo Welz | 801/P032 | 2814 | t.welz![]() |