ORNL-2106 - the Molten Salt Energy Technologies Web Site

ANP PROJECT PROGRESS REPORT
air and the fuel mixture seem to be surface active.
Air, of course, produces an oxide film which is
ever present, and the fuel mixture, in effect,
creates a very thin surface film by leaching one
of the alloy constituents and producing another
phase on the surface, as shown in Figs. 35.6
and 3.5.7.
SHORT-TIME HIGH-TEMPERATURE TENSILE
PROPERTIES OF HASTELLOY B
C. R. Kennedy
The short-time high-temperature tensile proper-
ties of solution-annealed Hastelloy B are illustrated
in Fig. 3.5.8, which gives the yield and ultimate
strengths and the final elongations in the temper-
ature range 1000 to 1800'F. As may be seen there
is a distinct decrease in the final elongation and
in the ultimate strength at temperatures around
1200OF. This change in properties occurs in the
temperature range in which the type of fracture
transforms from predominantly transgranular to
intergranular. . It is interesting to note that the
change in the yield strength with temperature is
relatively sma I I.
CR E E P-RU PTUR E PROP E R TI E S u
OF HASTELLOY W
C. R. Kennedy
Creep testing of Hastelloy W is now in progress,
and design data are presented in Figs. 3.5.9,
3.5.10, and 3.5.1 1 for solution-onnealed sheet
tested in argon at 1300, 1500, and 1650OF.
Hastelloy W, which has almost the same compo-
sition as Hastelloy 8, except for the addition of
5% chromium and the deletion of 3% molybdenum,
has creep properties very similar to those of
Hastelloy B. Although Hastelloy W exhibits less
of a tendency to age than Hastelloy 0, as shown
in Figs. 3.5.12 and 3.5.13, a decrease in ductility
occurs at 130O0F. This is also shown in Fig.
3.5.9, in which the absence of a 10% curve indi-
cates that the total strain at rupture was less
than 10%.
Rupture points obtained from tests with the fuel
mixture (No. 30) NaF-ZrF,UF, (50464 mole %)
are also shown in Figs. 35.9 and 3.5.10. The
times to 0.5, 1, 2, 5, and 10% total strain are
identical for the same stress and temperature,
and, as shown, only the rupture life is affected by
Fig. 35.6. Surface Effect on the Unstressed Portion of a Hastelloy B Specimen After Exposure
to the Fuel Mixture (No. 30) NaF-ZrF,-UF, (50-46-4 mole X) for 1700 hr. 1OOOX. (F
* I 'W
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