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ANP PROJECT PROGRESS REPORT
TABLE 3.3.6. RESULTS OF EXTRUSION EXPERIMENTS ON SPECIAL ALLOYS PREPARED V
BY BATTELLE MEMORIAL INSTITUTE
I
Alloy Nominal Compositions (wt X)
No* Ni Mo Nb Ti C Mn
Extrusion Conditions
Temperature Results
Ratio Rate*
e F)
8-2897 77 20 1 1 0.12 0.80 2060 5.4:l 3 Back of tube cracked on inside
2100 5.4:l 3 Bock of tube cracked on inside
8-2898 76 20 1 2 0.12 0.80 2060 5.4:l 3 Back of tube cracked on inside
2100 5.4:l 3 Back of tube cracked on inside
2 150 E1 2c Good tube blank obtained
2150 7:l 2b Good tube blank obtained
8-2899 78 20 1 0.20 0.80 2060 5.4:1 3 Back of tube cracked on inside
~~
2150 5.4:l 3 Back of tube cracked on inside
2125 5.4~1 3 Back of tube cracked on inside
2150 7:1 2% Good tube blank obtained
*Number of turns that the valve on the high-pressure water to the extrusion ram was opened; see discussion above.
present without adverse effect on corrosion re-
s istance, ternary alloys are being prepared that
will contain 17 wt % molybdenum, the elements
listed below in the amounts shown, and the
balance nickel.
Element to
Be Added
Quantity to
Be Added
(wt 96)
G 3, 5, 7, 10
w 2, 4
Ti 5 4
Nb 24
AI 2. 4
Fe 7. 20
C 0.1, 0.25, 0.50
Vacuum-induction heats of each composition are
being prepared in 3-lb billets. A small amount
of carbon is added to each charge to bring the
resultant carbon level to 0.06%. It is possible
to machine three tube-blank extrusion billets from
each ingot for the fabrication of sufficient tubing
to make three standard therma I-convection loops
for corrosion testing. Thus far the chromium-
bearing alloys have been prepared, as well as the
alloys with 2 wt % tungsten, 2 wt % titanium, and
2 wt % aluminum. Good tube blanks were obtained
166
by extrusion of the chromium-bearing alloys at
2100 and 215OoF. In all cases, a slow extrusion
rate of approximately 1 in. of billet length per
second at a ratio of 7:1 was used. Tubes 7 and 8
of Fig. 3.3.4 are representative product samples.
It is known that chromium additions above a
certain minimum amount are detrimental from the
standpoint of corrosion by fluoride hels, but
chromium is a desirable addition for imparting
oxidation resistance to the alloy. Results of
previous tests of chromium-bearing nickel-mo-
lybdenum alloys in the fuel mixture (No. 30)
NaF-ZrF4-UF4 (50-46-4 mole %) indicated that
chromium additions in excess of 5% caused de-
creased corrosion resistance; at least 7% chromium
is required, however, to make the alloy resistant
from an oxidation standpoint. The chromium level
that can be tolerated when the alloy is in contact
with the fuel mixture (No. 107) NaF-KF-LiF-UF4
(11.2-41-45.3-2.5 mole %) is to be determined.
In all extrusion experiments carried out this
quarter, difficulty was encountered occasionally
with billets failing to extrude to completion. This
trouble was attributed to excessive chilling of
the billets by the cold ram at the slow extrusion
rates being used. Therefore a new billet was
designed that has mild-steel nose and tail plates
tack welded to it. The plates were expected to
*