Effect of self-ion irradiation on the microstructural changes of alloy EK-181 in annealed and severely deformed conditions

Abstract

2017-08-30T02:06:54

Radiation Tolerance of Ultrafine-Grained Materials Fabricated by Severe Plastic Deformation

“…Recent experiments on steels exposed to huge doses of ion irradiation provided somewhat contradictory results. 48,49) A specially designed low activation steel, RUSFER EK-181, 50) in coarse-grained and nanostructured states was subjected to irradiation with Fe ions to as much as 400 dpa at 400 500°C. 48) The study revealed that nanostructuring accelerated the onset of swelling accompanied by significant thermally activated grain growth at high doses.…”

“…48,49) A specially designed low activation steel, RUSFER EK-181, 50) in coarse-grained and nanostructured states was subjected to irradiation with Fe ions to as much as 400 dpa at 400 500°C. 48) The study revealed that nanostructuring accelerated the onset of swelling accompanied by significant thermally activated grain growth at high doses. Radiation-induced voids in HPT steel were three times smaller but their concentration was noticeably higher than for the coarsegrained material.…”

“…In addition, the results of heavy ion irradiation must be analysed carefully with respect to the surface effect and do not directly correspond to the effect of neutron experiments for the reasons discussed in the next section. Finally, the experiments 48,49) were carried out at the temperature where the UFG material recrystallised, so two processes of irradiation and thermal grain growth could interfere and accelerate each other. Gigax et al pointed out that grain growth in the un-irradiated area of the SPD material was far less pronounced than in irradiated regions, 49) which leads to the assumption that irradiation can facilitate degradation of the UFG microstructure when the material is thermally unstable.…”

On the use of non-destructive, gigahertz ultrasonics to rapidly screen irradiated steels for swelling resistance

“…It would be immediately beneficial to have such a rapid gauging tool to survey the reactor's components for void swelling, consequently avoid operating the reactor beyond the critical incubation period when void swelling proceeds steadily. Still, until this inference model is developed and vetted, direct observation of void swelling will still be essential in baseline studies for new materials [19].…”

Effects of the Tempering and High-Pressure Torsion Temperatures on Microstructure of Ferritic/Martensitic Steel Grade 91

“…At the same time, it is recognized that the most significant grain refinement can be achieved by applying high-pressure torsion (HPT) [ 12 ]. The grain refinement to 130 nm in ferritic/martensitic steels produced by HPT was observed in [ 13 , 14 ]. Application of HPT to transformation induced plasticity (TRIP) steel leads to a gradual reverse transformation from body centre cubic (bcc) α’ phase to the hexagonal close-packed (hcp) ε phase [ 15 ].…”