In the 1st RP materials to be qualified and the welded joints of various kind as well as the protective coatings were developed and distributed to the partners to allow starting of qualification. Namely, slabs and plates of AISI 316L and 15-15 Ti steels were distributed both in the MYRRHA and ALFRED variants. The same materials were welded by TIG and SAW techniques which were optimized in the Project itself and also distributed to the partners for the experimental phases. The innovative GESA, PLD and Detonation Gun coatings for structural materials were developed and employed to protect specimens to be subjected to mechanical and corrosion tests.
To fully understand the occurrence of mechanical stresses resulting from the welding of thick mechanical parts and in order to qualify stress models developed by GEMMA partners, one of the two envisaged tests of neutron diffractometry was carried out. The technique is able to accurately assess the level of residual stresses, within a welded piece, by detecting the minimal deformations of the crystalline lattice.
Furthermore, to build thermodynamic and kinetic models for Fe-Ni-Cr model alloys under irradiation, the experimental studies of elemental diffusion phenomena were started over a stratified sample, produced in the Project, whose layers contain different quantities of the three elements.
During the 2nd RP, the corrosion-resistant coatings and steel alloys, which have been developed and produced previously, have been subjected to thermomechanical characterization tests. Most of the tests have been completed but some of them have been stopped by the COVID lock-down. The identification of the guidelines for the qualification of coatings has also begun.
The characterization tests of the welds in air were completed and the two corresponding deliverables were issued. The residual stress weld preparation report relating to neutron diffractometry tests carried out in the previous period was issued.
The experimental studies of elemental diffusion phenomena over stratified sample progressed. The Fe-Ni-Cr multilayer system has been optimized to obtain the required degree of purity. The ion-irradiation campaign on the multilayer system was started and completed. The annealing treatment has been started. The kinetic model for the iron-nickel-chromium system was developed and issued.
Compatibility tests within HLM of welded or coated materials under static and dynamic conditions have been started . The interim report on Modeling and microstructure investigations of the corrosion damage has been issued. The compatibility tests with high temperature helium have been concluded. The experimental data produced by ENEA, CNRS, CIEMAT, JRC, CVR, KTH have been uploaded into MatDB data repository.
In the third reporting period characterization tests of coatings and corrosion resistant steels have been completed. In particular, the long-term compatibility tests with HLM on coatings and welds were carried out .
The reports relating to the guidelines for characterization were issued.
The characterization tests of welds and base materials in the HLM environment have been completed.
The second test to measure residual welding stresses by means of neutron diffractometry has been completed.
The studies of the Fe-Ni-Cr multilayer systems have been completed and the reporting has also been concluded. The annealing treatment has been completed. The final report on modeling and microstructural studies regarding corrosive damage has been issued. The mechanical tests in the HLM environment were conducted and the related reports were issued. The implementation of experimental data supplied by all partners within the Mat-DB data repository, located at JRC Petten, was accomplished and the data were checked.
