ORNL-1771 - Oak Ridge National Laboratory

PERIOD ENDING SEPTEMBER IO, 7954
0.0i -
X
0
E
0.02 -
Fig. 6.4. Brazing Alloy A on Inconel T-Joint After Testing. Dark areas are not areas of attack.
Etched with oxalic acid.
as follows:
Carbon
Chromium
Tungsten
Molybdenum
Manganese
Si I icon
Nickel
Cobalt
Composition (wt %)
Heot B Heot C
1 0.30
35 28
5
12
0.50 0.50
0.50 0.50
3
58 55.7
The specimens were tested in static mediums for
100 hr at 1500°F. Inconel container tubes were
used and duplicate tests were run. The test results
are presented in Table 6.2.
Both Stellite heats were heavily attacked along
the carbide network in NaF-ZrF,-UF, (50-46-4 mole
%), as shown in Figs, 6.5 and 6.6. The attack
varied from a minimum of 7 mils to a maximum of
20 mils. The depth of attack varied with the orien-
tation of ihe carbide network with relation to the
0.03
specimen surface, being deepest when the network
was perpendicular to the surface.
None of the specimens were attacked in sodium;
however, in heat B there wgre no large equiaxed
carbide particles in a 1- to 2-mil area adjacent to
the surface. The carbide particles in this area appeared
to have transformed to a very fine structure.
There was also a large amount of fine precipitate
in the cobalt-rich matrix near the surface,
Heat C had slightly better resistance than heat B
to attack by sodium, and both heats had very poor
resistance to attack by the fluoride mixture. Several
of the specimens had shrinkage voids near the
surface, one that was 7 mils in diameter, and the
attack was deeper in these areas.
Hastelloy R in Various Media
Hastelloy R centerless ground and annealed rods,
in. in diameter and 8 in. in length, were obtained
from the Haynes Stellite Company. Each rod was
1 1 3
machined into a specimen (6 x 4 x 4 in.), a con-
tainer, and a plug. The specimen and the medium
to which if was to be exposed were loaded into the
85