Technological aspects in blanket design: Effects of micro-alloying and thermo-mechanical treatments of EUROFER97 type steels after neutron irradiation

Research output: Contribution to journalArticlepeer-review


  • Michael Rieth
  • Esther Simondon
  • Gerald Pintsuk
  • G. Aiello
  • J. Aiello
  • Athina Puype
  • C. Cristalli
  • L. Pilloni
  • O. Tassa
  • Michail Klimenkov
  • Hans-Christian Schneider
  • P. Fernandez
  • T. Gräning
  • X. Chen
  • A. Bhattacharya
  • Joel W. Reed
  • J.W. Geringer
  • Mikhail Sokolov
  • Y. Katoh
  • L. Snead

Institutes & Expert groups

  • EUROfusion 2020 - Euratom Horizon 2020
  • IKET KIT INE - Karlsruhe Institute of : Institute for Nuclear Waste Disposal
  • FZJ - Forschungszentrum Jülich GmbH
  • OCAS - OnderzoeksCentrum voor de Aanwending van Staal - Belgium
  • ENEA - Italian National Agency for New Technologies
  • RINA consulting - Centro Sviluppo Materiali S.p.A.
  • CIEMAT - Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas
  • ORNL - Oak Ridge National Laboratory
  • Irradiation Materials Sciences Consulting

Documents & links


Presently available data on neutron irradiation damage raise doubts on the feasibility of using EUROFER97 steel for a water-cooled starter blanket in a DEMO reactor, since the ductile-to-brittle transition temperature (DBTT) increases significantly for irradiation temperatures below 350.C. The additional DBTT shift caused by H and He transmutation can only be estimated based on very few results with isotopically tailored EUROFER97 steel. Conservative calculations show that the DBTT of EUROFER97 steel could exceed the operating temperature in water-cooled starter blankets within a relatively short time period. This paper presents results from a EUROfusion funded irradiation campaign that was performed in the High Flux Isotope Reactor at Oak Ridge National Laboratory. The paper compares ten newly developed reduced activation ferritic-martensitic (RAFM) steels irradiated to a nominal dose of 2.5 dpa at 300.C. The post-irradiation experiments using Small Specimen Test Technology included hardness, tensile, and fracture mechanics tests combined with fractography and microstructure analysis are presented. Results show that micro-alloying EUROFER97-type steels influenced the mechanical properties but a dominating impact on irradiation damage resistance could not be identified. In contrast, specific thermo-mechanical treatments lead to better DBTT behavior. Discussion about irradiation response to heat treatment conditions is also given. Despite requiring data also at high dpa values, the results indicate that with these modified materials an increased lifetime and potentially also an increased operating temperature window can be achieved compared to EUROFER97.


Original languageEnglish
Article number112645
Pages (from-to)1-11
Number of pages11
JournalFusion Engineering & Design
Publication statusPublished - 15 May 2021


  • EUROFER97, Thermo-mechanical treatment, Neutron irradiation, Post irradiation examination, Embrittlement, Fracture toughness

ID: 7277059