A systematic study of radiation-induced segregation in ferritic–martensitic alloys

Abstract

A systematic approach to measuring radiation-induced segregation (RIS) was used on four ferritic-martensitic (F-M) alloys: T91, HCM12A, HT9, and a Fe-9Cr model alloy, irradiated with 2.0 MeV protons over a range of doses (1-10 dpa) and temperatures (300-700°C). The experimental conditions are established so as to isolate the dependence of RIS on the experimental parameters: temperature, dose and bulk composition. RIS is measured at prior austenite grain boundaries (PAGBs) using the STEM-EDS technique. Chromium is found to enrich at PAGBs in all conditions with the exception being T91 irradiated to 3 dpa at 700°C. The magnitude of enrichment is small (<2 at%). Minor elements Si, Ni, and Cu also enrich consistently. A bell-shaped temperature dependence of RIS is observed in all elements. The amount of Cr enrichment decreases as a function of increasing bulk Cr concentration. Lastly, it is found that the 9Cr model alloy reaches a steady-state Cr RIS behavior at approximately 7 dpa, while the T91 reaches what may be a steady state near 3 dpa, then the amount of enrichment decreases at 10 dpa.

Chromium enrichment on the habit plane of dislocation loops in ion-irradiated high-purity Fe–Cr alloys

“…More recently, ab initio calculations have suggested that Cr RIS or RID is a competition between interstitial and vacancy mechanisms and depends on the relative amplitude between both [21][22][23]. This argument was used later by Wharry et al to explain their field emission gun/scanning transmission electron microscopy (FEG/STEM) X-ray measurements in a set of F-M alloys [24]. They showed that RIS would occur at lower temperatures when Cr is dragged by interstitial flux, while RID would occur at higher temperatures when Cr is dragged by vacancy flux.…”

Modeling Radiation-Induced Segregation in Binary Alloys

“…Для цього стану, як можна показати, градієнт концентрації компонента А пов'язаний з градієнтом концентрації вакансій таким співвідношенням [13]:…”

“…Експерименти показують [4][5][6][7][8][9][10][11][12][13], що під час опромінення сплаву при підвищених температурах (0.3 -0.5 T пл. ) [14] відбувається просторовий перерозподіл компонентів даного сплаву.…”

Nanoscale morphologies at alloyed and irradiated metal-oxide bilayers

“…Together, these two irradiations illustrate that phenomena such as intermixing at metal-oxide interfaces is very sensitive to the irradiation conditions. In particular, it has been established that temperature plays a very important role on radiation-induced segregation at these types of interfaces [29].…”