Microstructural evolution of welded stainless steels on integrated effect of thermal aging and low flux irradiation
Paper in proceeding, 2019

The combined effect of thermal aging and irradiation on cast and welded stainless steel solidification structures is not sufficiently investigated. From theory and consecutive aging and irradiation experiments, the effect of simultaneous low rate irradiation and thermal aging is expected to accelerate and modify the aging processes of the ferrite phase. Here, a detailed analysis of long-term aged material at very low fast neutron flux at LWR operating temperatures using Atom Probe Tomography is presented. Samples of weld material from various positions in the core barrel of the Zorita PWR are examined. The welds have been exposed to 280–285 °C for 38 years at three different neutron fluxes between 1 × 10 −5 and 7 × 10 −7 dpa/h to a total dose of 0.15–2 dpa. The aging of the ferrite phase occurs by spinodal decomposition, clustering and precipitation of e.g. G-phase. These phenomena are characterized and quantitatively analyzed in order to understand the effect of flux in combination with thermal aging.

Spinodal decomposition


Weld ferrite

Thermal aging

Stainless steel


Martin Bjurman


Royal Institute of Technology (KTH)

Kristina Lindgren

Chalmers, Physics, Microstructure Physics

Mattias Thuvander

Chalmers, Physics, Microstructure Physics

Peter Ekström

The Swedish Radiation Safety authority (SSM)

P. Efsing

Royal Institute of Technology (KTH)

Ringhals AB

Minerals, Metals and Materials Series

23671181 (ISSN) 23671696 (eISSN)

Vol. Part F11 703-710

18th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors
Portland, USA,

Subject Categories

Manufacturing, Surface and Joining Technology

Other Materials Engineering

Metallurgy and Metallic Materials

Areas of Advance


Materials Science


Chalmers Materials Analysis Laboratory



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