ORNL-1816 - the Molten Salt Energy Technologies Web Site

TABLE 7.4. STRESS-RUPTURE PROPERTIES OF
HASTELLOY B IN ARGON AT 1500°F
Stress Time to Rupture Elongation
(psi) (hr) (%I
15,000 157 45.0
13,500 180 15.0
12,000 1150 20.0
8,500 2200* 4.0
*Specimen stili in test.
The new alloys being developed are also tested
for stress rupture at 150OOF in argon in order to
check the effect on strength which results from
the various modifications. The results of tests
made to date are presented in Table 7.5. These
modified alloys show a decrease in high-tempera-
ture strength and elongation in comparison with
Hastelloy B in the solution-annealed condition.
SPECIAL MATERIALS FABRICATION
H. lnouye .J. H. Coobs
Metallurgy Division
Duplex Tubing
The efforts to produce duplex seamless tubing
that will have good oxidation resistance on the
outer surface and good corrosion resistance on
the inner surface have continued. In the previous
reportt3 tests were described in which hot-rolled
and hot-pressed composites were deep drawn.
3J. H. Coobs and H. Inouye, ANP Quar. Prog. Rep.
Sept. IO 1954, ORNL-1771, p 123.
PERIOD ENDING DECEMBER 70, 7954
tubing is now being used in which the composite
bi I lets are extruded.
A study of the flow of metals during an impact
extrusion is being made. For the study, the effect
of the shape of the nose of the extrusion billet
was determined on extrusions of Zircaloy ccinned in
copper and extrusions of vanadium canned in steel.
In addition, a two-ply and a three-ply billet of
stainless steel-carbon steel were extrud'ed, but
the extrusions have not yet been evaluated.
The results of the tests show that largegrained
billets, such as cast billets, produce 12 rough
interface between the outer cladding and the core.
A tapered nose on the can and a square (edge on
the core result in a short section of can material
restricted to the front of the billet; thereafter, the
core has a thin layer of the canning material on
the surface. A square nose on the can and a
tapered core result in a thin section of corle begin-
ning very soon after the front of the extrusion and
increasing in thicknesses toward the end of the
extrusion.
Boron Carbide Shielding
Suitable compositions for the boron carbide
shield for the ART heat exchanger are being developed
by The Carborundum Company ancl by the
Norton Company by using various noninetall ic
bonding materials, including BN, Sic, and carbon,
as well as those mentioned previo~sly.~ All these
bonding materials have been used to some extent
in fabricating useful forms of B,C. Another possible
source for fabrication of these shield pieces
is Sylvania Electric Products, Inc., which only
recently became interested in the problem.
In a recent conference with representatives of
The Carborundum Company it was stated that they
11.0
8,000 510 7.0
t