ORNL-1816 - the Molten Salt Energy Technologies Web Site

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ANP QUARTERLY PROGRESS REPORT
19.1
39.0 pg/cm2
tBERYLLIVM INSERT
LENGTH - 3.75 in
ID-04301n
UNCLASSIFIED
ORNL-LR-DWG 4650
ution of Beryllium Around an
oop Containing a Beryllium
m. Test period, 270 hr.
g. 6.2. Surfaces of Beryllium Insert from an
nconel Thermal-Convection Loop After Exposure
to Sodium for 1000 hr at 13OO0F. (u) Surface of
beryllium exposed to sodium in annular space.
(b) Surface of beryllium exposed to flowing sodium.
OOX. Reduced 37.5%.
under way to determine the minimum spacing that
can be tolerated between beryllium and Inconel.
STATIC CORROSION STUDIES
E. E. Hoffman
W. H. Cook C. F. Leitten
Metallurgy Division
Brazing Alloys on Stainless Steel
Additional tests have been made in an effort to
find a brazing alloy that has good resistance to
both sodium and the fuel mixture NaF-ZrF,-UF,
(53.5-40-6.5 mole %). The results reported in Table
6.5 were obtained from tests of type 304 stainless
steel T-joints brazed with the alloys listed by the
Wall Colmonoy Corporation. Tests are also being
conducted on Inconel T-joints brazed with each of
the alloys listed in Table 6.5. All the brazing
alloys listed had good resistance to the fluoride
mixture, but only alloy C-29 had good resistance
to both the fluoride mixture and to sodium.
Brazing Alloys on Nickel
A series of T-ioints of A-nickel were brazed with
the various alloys listed in Tables 6.6 and 6.7 in
a dry hydrogen atmosphere and were then exposed
for 100 hr to static NaF-ZrF,-UF, (53.5-40-6.5
mole %) at 1500°F or to static sodium hydroxide at
1100 and 15OOOF. The specimens were examined me-
tallographically in the as-received condition in
order to evaluate the inclusions and the porosity.
The brazed specimens were thoroughly cleaned
before and after testing so that Val id weight change
data could be obtained. In order to prevent the
rounding of the fillet edge upon polishing, each
specimen was nickel plated after testing. The
data obtained from metallographic examination of
the specimens exposed to the fluoride mixture are
presented in Table 6.6, and the data on the speci-
mens exposed to sodium hydroxide are in Table
6.7.
Most of the alloys tested appeared to have good
corrosion resistance to the fluoride mixture, except
the braze alloy with the composition 69% Ni-20%
Cr-ll% Si. Several of the brazed T-ioints, especially
those which included copper, gold, or
silicon as an alloying element in the braze material,
showed numerous voids in the interface between
the base material and the braze fillet. These voids
are not considered to be caused by the attack of
the fluoride mixture but rather by diffusion of a
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