ORNL-1771 - Oak Ridge National Laboratory

PERIOD ENDING SEPTEMBER IO, 1954
UNCLASSIFIED
Fig. 6.10. Carburization of Incornel Exposed to Sodium with Carbon Additions for 100 hr at 150OOF.
(a) inconel specimen before test. (6) Specimen tested in sodium plus 1 wt % carbon. (c) Specimen
tested in sodium plus 10 wt % carbon. Specimens nickel plated to protect edges. Etched with glyceria
regia. 250X.
and a “tough skin,’’ which, it was hoped, would
reduce penetration of various liquid mediums.
An open Graph-i-tite crucible containing sodium
and a sealed Graph-i-tite crucible containing NaF-
ZrF,-UF, were tested at 1500°F for 100 hr in
vacuum. The sodium completely penetrated the
0.38-in.-thick wall of the crucible, as in the pre-
vious test,’ and caused it to crack and crumble.
The only macroscopically visible sign of attack on
the crucible that contained the fluoride mixture was
that the inner surface had a higher gloss (Fig. 6.11)
after exposure, Metallographic examination of
sections of the crucible indicated irregular pene-
tration from 0 to 5 mils deep. No attempt has been
made to determine whether reaction products ac-
companied the penetration. This attack may be
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