ORNL-2106 - the Molten Salt Energy Technologies Web Site

ANP PROJECT PROGRESS REPOR7
cores were examined by x-ray diffraction tech-
niques for evidence of reaction. A reaction had
occurred in the COB,-Fe material during the fabri-
cation process that resulted in the formation of
Fe,B. No reaction was detected between BN and
nickel, in confirmation of the compatibility test
results for BN and lnconel reported previously.8
Clad specimens of both BN-nickel and BN-lnconel
have been prepared for irradiation testing in the
LITR.
The combinations COB,-Ni and BN-Fe were also
investigated. The COB,-Ni compacts formed a
liquid phase at 180OOF during sintering. No re
action was observed between BN and iron. Diffi-
culties in fabrication were experienced, however,
and work on the BN-Fe combination was discon-
tinued in favor of the BN-Ni composition. The
BN-Ni cermet appears to be attractive as a high-
temperature shield material, since it is easily fob
ricated and the components me compatible up to a
temperature of 2000OF.
Boron Steels
The study of boron steels for use in a compres-
sion ring between the beryllium reflector and the
support strut ring in the ART was continued. The
tensile strength of a cast 0.75% B'O-Fe alloy at
1300OF was 14,775 psi, with no elongation. Billets
of the alloy were extruded into rod at 1900OF with
no difficulty by using an extrusion ratio of 6.51.
Tensile specimens will be machined from the
wrought material to determine the effect of hot
working on the mechanical properties of the alloy.
The compatibility of boron-iron alloys containing
1 and 3% boron and lnconel was investigated in
506hr tests at 1300OF. Diffusion couples were
prepared for the tests by hot rolling the composite
material at 1900OF. Metallogrcphic observation of
the lnconel and boron-iron alloy interface revealed
that no diffusion of boron into the lnconel had
occurred during the hot-roll ing operation. Photo-
micrographs of the diffusion couple interface after
500 hr at 13OOOF are shown in Fig. 3.3.6. The
layers 1 to 1.5 mils wide in the 1% B alloy and0.5
mil wide in the 3% B alloy that were depleted in
boron after 500 hr at 13OOOF indicated that diffu-
sion of boron into the lnconel was not serious at
this temperature.
8T. K. Roche and H. Inouye, ANP Quar. Pmg. Rep.
March 10, 1956, ORNL-2061, p 157, Table 6.7
170
Radiation-damage specimens were fabricated from W
a boron-stainless steel alloy for testing in the a
LlTR and in the MTR. The composition of the
alloy is basically type 304 stainless steel with the
nickel content increased to about 14% and a boron
t
addition of 1.07% The boron addition to the melt
contained 84.6% B'O and 15.4 B' '. The specimens
will be irradiated unstressed and stressed at 500
psi at temperatures from 1300 to 1700OF in the
LITR and at 1600OF in the MTR.
Recent work by other investigators9 has revealed
low ductility in boron-stainless steels after irrq
diation. The feasibility of using a duplex ring
configuration is therefore being investigated. The
primary ring would be fabricated from lnconel and
the secondary ring from clad copper-B4C.
Other Boron-Containing Maierials
The electrophoretic deposition of uniform copper
coatings on ceramic B,C tiles and the bonding of a
copper-B4C layer to type 430 stainless steel is
being investigated by the Vitro Laboratories. Good
bonding of a deposited copper coating has been
achieved on cast and sintered B4C ceramic tiles.
The bonding of a copper coating to hot-pressed
B,C tiles has been moderately successful. Elec-
trophoretically deposited coatings containing up to
40 vol % of B4C particles dispersed in copper
shrank excessively during the sintering treatment
at 1000°C.
SOLID FUEL ELEMENTS
M. R. D'Amore J. H. Coobs
V. M. Kolbo"
The investigations of simulated seamless tubular
fuel element extrusions, reported previously, '
were continued The recovery of material with
uniformly thick layers varied from about 55% in a
tube extruded at a 5 1 ratio to a maximum of about
76% in tubes extruded at a 21:l ratio. Sections 18
in. in length from two tubes extruded at a 21:l ratio
were redrawn to 0.187-in.-OD, 0.015-in.-wall tubing.
Preliminary metallographic examination of the finished
tubing revealed a large number of tensile
failures in the 3Ovol % Al,O,-type 3028 stainless
'J. J. Lombardo, Tensile and Impact Test Results
on Irradiated Boron-Stainless Steel, WAPPSFR-FE-192
(June 28, 1955).
"On assignment from Glenn L. Martin Co.
"J. H. Coobs and M. R. D'Amore, ANP Quar. Pmg. .
Rep. March 10, 1956, ORNL-2061, p 161.
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