Effect of irradiation mode on the microstructure of self-ion irradiated ferritic-martensitic alloys

The co-evolution of microstructure features in self-ion irradiated HT9 at very high damage levels

“…Figure The results of this study are consistent with some other ion and reactor studies [3,7,75]However, it should be noted that the swelling rates observed in this study are an order of magnitude lower than recent results in similar alloys from Garner [42] and Toloczko [16] despite the higher dpa levels reached, but Several possible sources for these differences include heat/heat treatment [15], ion or neutron irradiation technique, and sample characterization method. Finally, the ion irradiations in this study were raster scanned at high raster scan frequency, which has been shown to delay the onset of void nucleation [12,76] and microstructural evolution, but there is no evidence of a difference in the high damage void swelling rate.…”

“…Ion irradiation, in addition to offering the benefits of accelerated damage rate and excellent temperature control, can provide systematic data sets that can be easily integrated into rate theory models [1,[12][13][14][15][16][17][18]. Furthermore, ion irradiation has been shown to be quite a successful method for emulating reactor damage especially for the purpose of materials selection prior to qualification of in test reactors [1,15,19].…”

Use of double and triple-ion irradiation to study the influence of high levels of helium and hydrogen on void swelling of 8–12% Cr ferritic-martensitic steels

“…The irradiation proceeded using a steady-beam, non-rastering approach in order to be compliant with ASTM standard E521-83, ''Standard Practice for Neutron Radiation Damage Simulation by Charged-Particle Irradiation'' that states, ''It is recommended that a rastered beam be avoided for the simulation of a constant neutron flux.'' [37] Beam rastering has recently been shown to strongly suppress swelling in both pure iron and in HT9 from the swelling observed in a defocused non-rastered irradiation [38][39].…”

Void swelling in high dose ion-irradiated reduced activation ferritic–martensitic steels

“…The 0.26%/dpa swelling rate was reported in bcc pure iron irradiated by 3.5 MeV defocused Fe ++ beam [11]. Relative to defocused beam or neutron, the raster-scanned beam used in this study may suppress the void swelling [17,18].…”

“…4. The determination of the ''effective irradiation region'' was detailed by Getto [13]. 500-700 nm was chosen for a nominal swelling value to achieve the highest possible dose and limit the dose variation.…”