Environmental Engineering Reference
In-Depth Information
Figure 9.3
Temperature dependence of swelling in ion bombarded and neutron irradi-
ated type 316 stainless steel, Ref. 12.
However, void swelling has been observed under conditions of damage rate,
temperature, and sink density at which the vacancy supersaturation should be too
low to nucleate voids. Helium gas that is produced by a transmutation reaction
is believed to aid void nucleation in such cases.
9.4.2 Control Through Metallurgical Variables
Metallurgical variables such as cold work, grain size, and composition have a
distinct influence on void swelling.
Cold work brings about a reduction in void swelling, but this effect is lost at
high temperatures and at high neutron fluences. Higher amounts of cold work
will be necessary to bring about a reduction of the same level at higher damage
levels. Cold work increases dislocation density in the material, and it has been
