Contact

Dr. Eberhard Altstadt

Head
Structural Material­s
e.altstadtAthzdr.de
Phone: +49 351 260 2276

Porträt Dr. Kaden, Cornelia; FWOM

Dr. Cornelia Kaden

c.kaden@hzdr.de, c.heintzeAthzdr.de
Phone: +49 351 260 3431

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 conduct the multi-scale characterization of irradiated reactor materials. 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 (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 of damage mechanisms and unravelling structure-property relations­hips. 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 Centre for ion irradiation experiments.


Our expertise:


Current projects

  • INNUMAT (EU HORIZON-EURATOM, 2022-2026)
  • ENTENTE (EU-H2020-Euratom, 2020-2024)
  • FRACTESUS (EU-H2020-Euratom, 2020-2024)
  • STRUMAT-LTO (EU-H2020-Euratom, 2020-2024)
  • WetAnnealing (BMWI, 2020-2025)
  • IOANIS 2 (EERA-JPNM Pilote Project, 2023 - 2027)
  • INSITEX (EERA-JPNM Pilote Project, 2023 - 2027)
  • SHERPA (EERA-JPNM Pilote Project, 2023 - 2027)

Latest Publication

Microstructure-informed prediction of hardening in ion-irradiated reactor pressure vessel steels

Lai, L.; Brandenburg, J.-E.; Chekhonin, P.; Duplessi, A.; Cuvilly, F.; Etienne, A.; Radiguet, B.; Rafaja, D.; Bergner, F.

Ion irradiation combined with nanoindentation is a promising tool to study irradiation-induced hardening of nuclear materials including reactor pressure vessel (RPV) steels. For RPV steels, the major sources of hardening are nm-sized irradiation-induced dislocation loops and solute atom clusters, both representing barriers for dislocation glide. The dispersed barrier hardening (DBH) model provides a link between the irradiation-induced nanofeatures and hardening. However, a number of details of the DBH model still require consideration. These include the role of the unirradiated microstructure, the proper treatment of the indentation size effect (ISE), and the appropriate superposition rule of individual hardening contributions. In the present study, two well characterized RPV steels, each ion-irradiated up to two different levels of displacement damage, were investigated. Dislocation loops and solute atom clusters were characterized by transmission electron microscopy and atom probe tomography, respectively. Nanoindentation with a Berkovich indenter was used to measure indentation hardness as a function of the contact depth. In the present paper, the measured hardening profiles are compared with predictions based on different DBH models. Conclusions about the appropriate superposition rule and the consideration of the ISE (in terms of geometrically necessary dislocations) are drawn.

Keywords: reactor pressure vessel steels; ion irradiation; microstructure characterization; transmission electron microscopy; atom probe tomography; nanoindentation; hardening

Related publications


Team

Foto: Gruppenbild der Abteilung

Head

NameBld./Office+49 351 260Email
Dr. Eberhard Altstadt801/P1512276
e.altstadtAthzdr.de
Dr. Cornelia Kaden801/P1023431
c.kaden@hzdr.de, c.heintzeAthzdr.de

Employees

NameBld./Office+49 351 260Email
Dr. Frank Bergner801/P1503186
f.bergnerAthzdr.de
Dr. Jann-Erik Brandenburg801/P1522301
j.brandenburgAthzdr.de
Dr. Paul Chekhonin801/P1462149
p.chekhoninAthzdr.de
Vanessa Dykas801/P1053363
v.dykasAthzdr.de
Mario Houska801/P1482242
m.houskaAthzdr.de
Libang Lai801/P1533032
l.laiAthzdr.de
Jens Pietzsch801/P0322814
3550
jens.pietzschAthzdr.de
Dr. Andreas Ulbricht801/P1463155
a.ulbrichtAthzdr.de
Tilo Welz801/P0322814
t.welzAthzdr.de