Abstract:
In an earlier report, the mlcrostructureswere examined for a series of Fe-15Cr-XNi (X - 15, 19, 21, 30, 35,
45, 75) ternary alloys and a 15Cr-85NIbinary alloy after Irradiation in the EBR-II reactor at 510 and
538"C.{I) At 510°C it was obvious that void nucleation was comp|ete prior to the onset of steady-state
swelling at all nickel levels, implying that some process other than void nucleation determines when the
relativelyrapid void growth associatedwith steady-state swelling occurs. At both 510 and 538°Ca pro-
tracted loop dominance at intermediatenickel levels was observed in the dislocation microstructure along
with a relatively low void density, suggesting a reduced bias toward preferential interstitial absorption as
a possible mechanism to produce lower swelling in this nickel range. The void densities also closely mir-
rored the total swelling behavior as a function of nickel content. Figures I-4 show the relationships
observed between loop and void densities, swelling, dislocation density and matrix nickel content.
