NATIONAL
ADVISORY
COMMITTEE
FORAERONAUTICS
_—.
TECHNICALNOTE
cm
C2
m
cm
No.1380
,
THE 1350°
F STRESS-RUPTURE
PROPERTIESOF TWO WROUGHT
ALLOYSAND THREE CASTALLOYS
ByE.E.Reynolds,
J.W. Freeman,
andA.E.White
University
ofMichigan
wl!!v
Washington
November
1947
.
-7
..-r’“-
4’
-,
—
..
. ..
-.
.-,--...~TIONAL~SORY
. . COWV
.,”’
-., ----
●
-,.
.
,-
.,
.
✎
✎✎
—’
.,.
TBE1350°F STRE~
-
.
‘
‘“.
‘.,~CHNIC&
NOTkNO. l@Q
,,
.
FORAERONAUTICS
.,.
.
z
. ..
,,
.
X!ROFERTIXS
03’
TWOWROUG3T
=s.,.-~ +
‘(MST
ALLOYS
.-.
.’..
ByE.E.’
Reynolds,
J,W.Freemanz
andA.E.White
.
.
.
.,.
,“
,.
s“a4MAiY
.
. .
. . .
.
........+
,.
. -....:-=.
,-.
“
,
.
.. .
..:-..
.,
:. ..’
:..,”,..:-.
.
The&pture-test
ch~acteristics
a~13506F oftwo’
&o~;~,a~o~s;
NR-82(605g
“modif
ied-lqw
tiarbon)
andNR-84(N-155
-smdified.-low
.,carbq$~,
andthethreeprecisiom-cast
ailoys,
NR-71
(X-ko),
N%87(~~=~. :.,:,
base+io
) ad NR+O (Co-Cr-Ni
bas6-5Mo,
m) hew.beendel%rmi’~d~’,
~~”
twowrou@talloys
were“tested
in *8 solution-treated
m-dagedconilly
tionandthecastalloys
wereagedbefore
testing.
Theprincip&i
-“
resuitsobtained
were:
#-
.,y,r,::
. . -. ,:
-..
.
.
.’
,.
,.
>1
,., ,. ,,,
‘ ~ :~~~e?y~;h at1350°!~,; . ,:
., .
..-.
j~.~r~ - ?..”:”
“’loohr
.,,
.
.
,,
...
.
32,
>oo.,, ;.24,000.
I’iro,ught
NR-Q2
‘. , .’.
,
.,.
.
,.
,.
.>.,.’,
24,000
~m”tl@t’
NR+34
32,500
“’
‘..:.
,L
,Ailoy
,,
.. .. . .. .
,, 1“ Castmqi
,“
.,-.
.,‘ ‘Ca6t
,“.NR+”
Cimt“m-go
.
*
*
,. ..-.
.
45,000.
‘
33,000
36,000
“““
4b,
500
.,,
41,”&o‘“ .’34,000
‘‘,
,,.,.
.- .
. .
.,
Theseproperties
compare
favorabl.y
withthoseofthestrongest
similar
alloys
previousl&.
M*e8tiiBate&.
“‘Ecm@v@r,
coqmjed+itha
60Cr+me-15140
alloy,
thethreecobal+chromium—m
*ckelcast&illoys
are
inferior.
,.
2
. .... ..
NACATNNO.1330
—
..
A correlation
ofNAw andOSRD(Pj.*o~ect
NRC-8)
dataispresente~
showi~~
thevariaticm
ofrupture
strengths
withtemperatuz%
inthe
qe of 1350°
to2000°
1?forthealloys.
iNTRoDucmoN
““
A pro~rsm
ofresearch,
whichhasasitsaimthedevelopment
of
better
alloys
foruseat theelevated
teqmmturesenoomt-ered
inthe
present-day-air’craft.
powerp@nts,isinprdgress
underwe sponsorship
andwith’
thefinancial
assistmce
oftheNational
AdvisowCcmmit~e
for@mma@ics at the‘Wnive&sity
of?iichigan.
As partofthisirkvesttgatioll,
ther@ture-t@
t cha~acterfs%iti~
oftwo“new
wrought
alloys
andthreenewcastalloys
werestudied
at13X*3?.Thisworkwasbegun
because
tie1~00°and1600°F propm’ties,
detmmincd
intheCSRDresearch’
program
(references
1 &d 2) show&d
these‘to
bepromising —
alloys.
.
TEST141n!ERrALs
Fivealloys,
twointhe wrought
for?+
andthree.
aScastings,
were
submitted
as testspecimens
intheheat-treated
condition
by the
National
Research
Council
(Project
NW-8). Qnlymaterial
sufficient
forthe1350°
F rupture
testswa8supplied.
Chemical
analyses
of‘the
‘five
alloys
are2ivenintable1. The
twowrought
alloys,
NR-82andN%84,aremodif
Ications
.oftwoalloys
previously
j.nvestigated,
NR42 isAlloy60Z in whichthecarbGn
was
lowered
from0.h6to0.i7yercent
andone4mlfofthe.
6 percent
molybdenumreplaced
by 2 percent”
tungsten
and2 percent
cokmbium.NR-8k
isa modification
ofallo~~
~-1~~inwluchthqcarbon
is.
0.14peroent
instead
of0.35percent;
“chromium,
nickel,
@ cobalt
eachraised
from
20to23-24@ticent;
and.
theno~bdeqbv~=tin<olwbilmratio
changed
from 3:2:1to 4:1:2.mo c@Btalloys,
NR-71(X-40),
NR-87,
basaalloys
xLthvarying
amounts
andNIL90,arecobaltihromimmai.ckel
of.
molybdenum,
andtun@ten.
Manufacturing
procedure
andheattreatment
ofthefivealloys
aro
as f01.lows
:
●
A
-.
.-
3
NACATNNO.13@
*
..
—
Alloys
NR-52andNR-8b
wereproduced
by theUnionCWbideand
C-arbon
Corporation.
Tney’wexe
melted
as3.00-pound
basic
induction
heatsj
hot-f
urgedfrom2100°@ 1400°F from
>inch-equare
ingots
tol-inch-square
bars.Bothalloys
weresolutio~treat+
1 how at2200°X’$yate~uencheilj
and.
aged5dhoursa% 1350°F. Testspecimens
0.250
.anch
in
dhmeterwbremachined.
fromthel-inch
bars.
,.
‘ Alloys
I@-71,
l&87y
’and.
NR+Owbreproduc@by the
Ha~es-Stellite
Company.
Theyweremelted
asZ&-pound
heats
inan $ndirect
arc-rob~+~
furngioe
~d’precision-cast
as
O.250-inch-diameter
testepe&[email protected]?lne
spec~.mms
werewed
50ho~s at2350°F lefore
t~sting.
--—
PmmmtE ., “
.
.
.
Stress-lwptum
tests
at 1350°
F wereruntoat least1000hours
to determine
tierupture
stren@hs
forthefivealloys.Thelongestitim3rupture-test
specimen
ofeachalloywasexeui~ed
metallo@a@~
ically
and.
itshardness
d.etemuinbd.
Therupture
testswereconducted.
asfolZows:
Thestress
wasap~liedtothespecitin
byweights
acting
through
a simple
beamana
system
ofknifeedges.Thespecimefi
wereheldattesttemperature
fcmapproximately
24hcturs
before
application
oftheloadtoallowfor
tempe=tmre-distribution”
aajustments.,
Tim elon$ati.on
datawereobtained
forthetestsbymeasuring
i+ie
dropof.theload,ing
beamduring
“ thetest,
Thelcmgest-tims
rupture-test
speilmen
ofeacla
material
wassectioned
longitudlna.lly
adJacent
tothe”
fracture.
Phototicrographs
ata
100-diemeter
magnification
wergtakenofthefractured.
portion
ofthe
sgecimen
andata 1000-diarcetey
ma&ification
oftheinterior
6trUCtUXe
ofthesp43cimen
nearthefracture
.Vickers
hardness
testsweremadeon themetallographic
specimens.
..
..
“REsuw’s
The1350°
F rupture-test
“results
forthef~veallays
s%~tidare
givenintsbleIT. Thesedataareplotted
infigure
1 onlox thmic
coordinates
ofstress
aga~nst
timeforrupture.me rupt~ s@er&hs
and.
theestimated
rupture-test
ductilities
at 100,50Q>andWOO hours
areg$.ven
intable111.
.-
.
4
.
NAC?A
TNNo.13@
The’
twosolutio.&treated
andagedwro~hta.lloYs,
NR-82(6059
modified-low
carbon)
~ NRg4 (N-155
modified-low
carbon),
gaveidum
ticalrupture
strengths
Of 32,
fjoo
pf3~
“fOr
ru t~ inlm h-# and
24,000
psifor30Q0-in~
rupture.
3 2,however,
~lqy“RR
haaan~stimatedelongation
to rupwe in10QOhotisof9 permnt,comparGd
with
30percent
foralloyNR-84.
F
‘I’he
threecastalloys
hads@z@hs ranging
‘from
.$1,000
tok5,
OM
psiforrupture
in100hoursand33,000
to36@O0p~i’
forrupture
in
1000hours.At‘1OO
hours,
alloyNR-71
(X-hO)
hadthehighest
stre@h,
W% forlowertimepe~i~de
~Qy NR-87
wasthe&fnxmget3t.
Comparative
estimated
elon@ztons
torupture
in1000hourewere40,1$,and8 percentforalloys
IW-71
(X-M)j NRA? (CO-CZ+’W
hase+fo
),andNR+O
(Co-C*Ni
base+lqo,
al),rea~ctively.
Fhotcmicro~raph6
ofthelongest-time
r~@lu?cH7Gst
specigmn
ofeach
alloy”
“at%
showninfigimes
2 and3. Inasmuch
5SOtiY‘kid-f
iciont
m&ti3rialfor‘the
rujpture
te~tswassupplied,
nome+%llographic
[email protected]
of
theori&inal
materials
couldbeprbpared.
Represmtative
original
microstruc
turesof soxw ofthesealloys
canbefotidInr9fexwnco8
1
and2.
,.
Vickeys
hardness
values
determ’l~d
ODthemot~lographlc
ipoctmns
aregivenunderthecorresponding
pho+mmimogrcphD
infigures
2 and3.
,
.,,
*
‘%
DISOWSION
OFREEWIZ!S
.. Thefivealloys
in~estigated
hadre~tively
highrupture
strem@hs
at1350°F on thebasisofa comparison
wi& fiveotheralioye
previously
investigated
(reference
3). (Sac
@ble’HZ.) “Thesefive
alloys
whiohhaveshowrl
excellent
properties
‘kre:~-1~~andcast6059, .
alloys
ofwhichthetWO: kiought alloys &de modifications;
thestandard
low-carbcn
K-1>5;
cast4.22-19;
ad [email protected]~1~lo.o
..
>.+oy.
,. ’t,..
;..”.
..
kkmghtalloyNR-8k(N-155
Wmfied-lowcarbon)
hadrupture
StZWD@@at~3500F approxi,~te~
ko~ psi@@er th~ thes~t~d
wZou@talloyN-1~~whenhot-woik~d,
tiecontition
whichgavethehigheststrengti
forN-155
at1350°
F. Ztwasalso
somxdmt
@r0nf3er
than
low-carbon
11-1~~
wi,th
a heat&?ea*nt sw~
~ mat of
wrcught
alloy
NR~4. Itthere
foti’
beems,”:
froma strength
stc=d&oint,
fiat~@ cow
position
modification
ofI@/-8k
waetenefici~.AI.~cu@~ble 11~
shdw-s
that
Westiengti
ofk~ioyNI+84
WaStich”
l“m& thestrongestcondition
(h-r fo&od)~portedfor”
ldii%ar~on
~“l~!%
th’is
Wtictiw heatwasworkedflo~tO 13500
F andhadexcessively
high
hotioldwork.
strengths
“due
tothie
.
k
.. . .
.
‘.”
NACATNNo.1380
.:
5
No comparison
ona similar
treatment
basisispossible
f’or
wrought
alloyNR-82(6059
modified-low
c~bon),because
theunmodified
60~ alloyhas”
notbeentested
inthewrought
condition.
It d.oes.
have“lower
streQ&th
,% castetandard
6059.Howeverj
castings
usually
haveJ
higher
rupture
strengti,s
at 13500
? than
.wrougQt
maisrials.
.
“Thbcast alloyshad slxisikr.
rupturestrengths.
Vsxiations
in
rupture
thws frcrn.
those~redicta@
by the.
ruytux%
curve,
whichwere
yossibly
duetovarying
c~stalorientation
between
specimens,
makeit
impossible
toattributm
theslight
streng~Ufferences
obs&vedto
..
chemical”
composition.
.
. .
..
,.,
,.
Thestrengths
of,thesethreealloys
areofthe,sameor&r ofrmg~“‘
nitudeas“that
of-thebestca&’c“bbalt-chrom~ickel
base@lox
(422-19)
‘@?evibusly
tested.
at 13500
F. They
have
rmzch
lowerstren@h,
howeverl
than‘cast
6oCr-2~e-l~:j
whichisoneOfthehighest-streng~.
,...
alloys
.
.. . .,., .,
.. k.hti’,
.,.,
T@-elongation
curves
from thempturatests
on.
thetwo.
tio@hk
alloy-s
.s~owed
thatthealloywithlo~r“d~~tility,
NR-82(6059
modifi&ilowcarbqti~,
hada lowerdeformation
&l@ thandidalloyNR-84(N-155.
modified-low
earbori).
Thiswastruealsoforthelowest-ducttli~
cast”
alloyNR-~O,,compared
with NR-7L
a@ I&&/.Attention
iecalled
to,
t@,
factthatthespecitin
ofalloyI!&71
(X-40)
under32,500
psi hadexceesively
h$gh elongation.
Thefracture
of thisspecimnwasof the
single-crystal
type,namely,
anoval-shayed
.f
ormation
ofthecryetal
ad~acent
tothefracture.
This.explaim
thehighductility.
-.
Metallographic
examination
ofthelonges%time
rupture-test’
specimensrevealed.
a matrix
filledwithfinsparticle
E ofexcess
constituent.
Thisistheusual appearem,ce
of long-time
rupture-test
specimens
ofalloys
ofthistyye,thefineparticles
precipitating
during
thetestandincreasing
thehardness
ofthematerial.
This
precipitation
isconsidered
tole an influential
factor
inthedsvQl~mentoftheoutstanding
properties
ofthesemterials.
.
.
A correlation,
whichshowsthevariation
inrupture
strength
with
temperature,
“obtained!
fromtheresearch
program
at1500°,
1600°,
and
2000°F 4references
1,2, -a 4)w$th
theNACAdata
at1350°1700°,
Aceml1800F,isshown
infigure
4 ~ort~erivedd,oysstudie~.
tually
theonlyalloyforwhichruptmestrengths
areava~lable
over
the,
complete
temperaiyme
rangeisNR-~1(X-kO).Onthebasisofthe
dataavaflable,
theothertwocastalloys
wtthstrengths
of thesame
orderofmegnj.tude
wouldbe expected
tovaryinstre~th@th te&
perature
toaboutthesameextent
@s~.-7l.AlloyNR-71,
incident-,
wasthestrongest
ofa groupofcast’
alioys
tested..at
17@ and1800°
F. (Seereference
4.) Thetiowrought~loyp,
NR~2 a7@NR-8k,
had
practically
identical
rupture
.stre@hsat both1350°and1500°F.
Higher-temperature
datahavenotbeen@termined
onthesetwoalloys.
NACATNNO.1380
..
CONWUSIONS
‘ ‘
,
,’
.“
Fromanitive~tig~t~on,qf
‘f&Strqss--rupf%re
ptiperties
at1350°F
of twowrouglit
alloys
+ thmO p~c:sion-c@ial
loys,”thefollowing
conolusj.ons
weremade:
Thetwowx%ugh$
alloy6~”
@82 {6059modified-low
carbon)
&dl&84
(N-155
modified-low
carbon),,
had~dentioql
1350°F rupture
strengths,
althou@,
al.loy
N&8khad,
muchhigher
ductility,
Thestrengtia
ofthese
aLloy8
arescmmwhat
higher
thanthoqeofstandard
N-155,
al@, butit
is~&herdoubtfql
whether
thig~eqefit
Issufficient
towarrant
the
necessary
increasein alloy content.
TM @reeprecision-cast.
a.llqw$
NR-’71”(X40)j
NR~7(C~~i ,
b~e-~Mo,5W)had1350°F rupture
base+lo)j
andNR-$10.
(CQ-CY+U
streng~s
whichqopqyared
favorably
with,tho$e
ofalloy422-19,
thebest
cobeJ.~.@o?yi-c~el.base
+loy previously
investigated
at1350°F.
Thbghwe much
lower
Strengths
however,
thantheUestchromiw+base
alloy@. Although’
there wem some difference
inrupture
strengths
among
the.
thz%e.cast
alloys,
thereme nota co~sistent
.variation..
Other
f~tors,suchas”vti~tlons
poesibly
duetova~Ji~cryetal
orientattonsbetweefi
s~cinlens,
makei-t
i?npoqsible’
to”attribwt.e
strength
differences
obsezwed
tochemical
composition.
,
.
..
‘%
University
ofMichtgan
15, 1946
~&?bor, ~ch.,~ovember
.,
.
..
.
.. . ,.
,
.
,.
.,..’
-.
,,,
..
.’
. .
,..,
r
‘.
. .
“....’
.
.
.
NACA~ NO,1380
‘7
.*
IUWERENCES
1.
Cross,
HowardC.,andSinunonsj
Warcl
F.: Progress
ReportonEeatResisting
Xeta,ls
furGasTMxinoParts(N-102).
NWRCOSRDRep.
No.b~l~,Ser.
-No..
*477,Feb.20,1945.
2. Cross,Howard
C.,andSimmons,
WardF.:FinalReTort
onHeatResistingMetals
for~asTurbine
l?~ts(N--102).
NIIRCJ
OSRDRep.
NO,6563,Ser.No.1&636,
Jan.21,1946,
3.Freeman,
J.V.,Rote,
)?.
B.,andWhite,
A.E.:HighTemperature
Characteristics
of17Alloys
at1200°
F and1350°F. NM2AACJ3
No.4C22,
19hb.
h.Freeman,
J.W., Reynolds,
E.E.,[email protected],
A,E.: TheRup~
TestCharacteristics
ofSixPrecision-Cast
andThreeWrought
Alloys
at 1700°and1800°F. NACAARRNo.5J16,1945.
~.
.
.-’
.
.
.
E.E.,andWhite,
A.E.:
Weernan,J.W,,Reynoltls,
AnInvestigation
oftheHigh-Teraperature
Properties
ofChromiu&Base
Alloys
at
1350°F. NACATNNQ.1314,
1947.
AIJm’IwEm
AT133PF
CEmfmL CCMWXTI oi’icw
chemical Composition
(percent)
c
lb
SI
m
Cr
0.17 1.20 0.69 25.29 9.0
(60f@xm3&ie&low
(w+5T&&fwOw
co
n
m
(n
lb
30.83 3.35”.2.23 1.03 —
‘2
0.03
carbcm)
ER+l (X4)
24.38
4.25
1.26
1.10
—
9.69
95.23
—
7.23
—
0.55
—
22.9
19.17
ml.
.9.09 —
—
.9
—
=.60
S.23
al.
5.qJ
5.1.8 —
.8
“—
.14
1.11
.48
.64
.’f%? S.I.2
.52
.-(0
.69
.44
.76
.m
Cal-blm)
.57
23.08
23.82
,14
(bG+Ji M’m+b)
T&l
baea+!b,
5n)
lrAmmAL Amtsm
CQMTI!EE m
AERmmrxcs
9
NACA TN No.1380
—
-c
.;.
stress
(Psi)
Kuoy
wrcn@tIm432
(@g m?dfied-low
mbcm)
wrought
m-ah
(%155
@fled-low
oarbon)
cast
NR+l(X*)
Rupture
tim
(w)
44.5
229
291.5
25,000
725
9
10.5
10.9
12.5
12
33,000
lM.
26
26.5
30,000
27,009
25,000
196.5
338
718
33
a30
39.0
2L2
28.2
35,0@3
32,5-00
Castm&87
J
(~
bsse+b)
37,~
35,000
34,000
i
&Stm-go
(w+h+f~b~,
45,
Oco
40,000
X)
k5,000
., 40,00a
37,500
35,@3f3
34,0Q0
.
x
32,500
%ksctmd~
9
a8
a29
100
232
816
lug
x
18
27
u
84
20
17
22
13
33
27.0
%3
8.5
IQ
15
8
2Q.i’
7.0
378
775
918
lgao
53
84
542
639
960
1630
gs&s
mrk.
NATIONALAnvmoRY
ccMal’lmFORAERoNmHc2
...
10
Reduction
of area
(peroant)
35,000
30,000
28,000
45,0fM
40,000
.
Elongation
In 1 inoh
(prcent)
7
40.7
37.7
35.0
45.6
27.4
31.8
33.1
35.0
13.3
16.5
10.2
6.4
10
NAC!ATN No.1380
TABL2.
111
..-’
-
.—
-—
.
RuPrumPRoPERrIsS
cFcAsTAm#KxMsT
mOYs AT13500FAND
CCWAR4TIW
moPERImsOF0m2sAIuJx8
TrOa*nt
w
(6@gmdifiecl-lcw
c*)
+SObrat13w° F
(yi)
Sswmsted
elcms&ion
to
rupture
inMoati&
tinu
~riode
(peme.t)
100br
SOOhr
lm hr
100b
5oohr MOO h’
32,500
26,000
24,
W
10
9
9
32,54XI
26,m
24,
COO
29
30
30
25
40
2200° F 1 hr V.Q.
Wwughtm-8k
modified-lew
-es)
cut m+
Streils
forruptuxe
in InMoatell
timperiode
E&30°
3’1hr U.Q.
L&ought
!!s-82
(%15S
.
+YOhrat1350°F
(x-b’o)
F
50hrat1350°
45,0C0 36,500 33,@3fJ31
50hrat 1350°~
44,500
38,0CW
36,
0@2
20
20
18
5ohrat13500r
u,m
36,
oco
34,Cm
10
10
8
Cae-b
IB87
(Ce-&-Ni
bas~)
Caet
S&go
Ims+5M,
5’.0
(O’=+J+Ni
.
mO@ltN-155*
Eot%mrkwl
28,000
22,000
20,
Oixl
.
Hrooght
I.OwOarblm
&l!&
lf-~c
F to1350°3’
36,000
w,Ooo
30,
CKKl
25,
%@
Zast60na
501mat1500°
F
36,m
32,500
:aet42s19=
50b at l~” F
47,
m
39,5Q3
L
b
n,w
17
3.2 ---
26
3S
a,
18
23
---
36*OW
28
la
10
----- ----- -
69,
OCM ‘56,500
52,009
4
5
‘i
22,800
b30,
XQ
%ta t9ken
~ reference
3.
bobtidby atrapOld.iOB
6
2200°1?1 hru.%
+f0bxat13x° F
ifm-fma-l%bd
6
Eamwr fe.rgd frmo
=Cd’
~rm@t~mben
10
Of StlW3~p~
1
.
OKWW .
x
‘I&ta taken fmm
Uiohifpn for
unreported
Invewtlgatien
en&piealI.ow-earben
W155 bareteokinprogrees
at theUniversity
of
theNACA.
%atataken fromreference
p.
IwmXiALAImscRY
CCWITUEFOSAESCKAVI’ICS
.
,.
.
1
I
#!-%%-l
Type chemical
Heattreatment
Alloy
IWw 1 4* 1
0
a r
at
0.1726 3; 31 4 2:2 1.0 0.;2 220
❑ WroughtHR-82
at
4.2
1.3
1.1
.1423
24
24
220WW
1
hr
%.&+50
hr
14
A WrouihtNR-84
.48:
2510557.250
hr
at
135@F
o castNR-71(Xao)
.52!
2319
9
- - 50 hr at 1350°F
x CastNR-f17
.441231181B~5 [5.21- I - 150hr at 1350°F
● Caet NR-90
●
I Lad
60,00(
~ 50,00(
G
.40,01X
:
*:30,()()(
01
20,00(
2
)
4
6
8
100
2
4
6
8 1000
2
Time, hr
Figure
l.-
Ourvesof streseagainstrupturetimeat 1350°F forwroughtalloyshlR-82
and NR-84and castalloysllR-71,
NR-87,and NR-90.
.
+
.
.
.-
NACA TN
No.
13
1380
6
Fracture,
100X
.
J
Interior,
1000X
under 25,000
psi;
(a)AlloyNR-82
. 725hoursforrupture
Vickers
hardness
294.
u
alloys
of specimens of wrought
Figure2a,b.-Microstructures
NR-82(6059modifi
cd-lowcarbon)
andNR-84(li155modified-low
carbon)
aftercompletion
of 1350°F rupture
test.Electrolytic
chromic
acidetch.
.
.
.
15
NACA TN NO.1380
Fracture,
100X
.
.>
-----
Interior,
1000X
(b)Al:;:r:R--:$-:::
~~s
.
forrupture
under25,000
psi;
Figure2.-Concluded.
?-
.
.
.
●
NACA TN
No.
1380
“-l
-b
PL-
.—
y,
r
Fracture,
100X
C-&iz
–-— .
%?
.,..>-●
,.:-.
>
2;.-. .>
.
“-.?..””
+-.
.-.,.
~,<.
.,-. “—.
.“
.
J
.
,-..-..-4
.
+ ,.-.20-..
.. -. . +’
. .
,.. .
i, .>:
“:-L?- .-. <<,-*
,.. ,,. .
. .s.:
. . ..;.j
...
. ..+
.“,
. .
.4
.“.
.l. ‘---.&
.
.
*
Interior,
1000X
under32,500
psi;
(a)AlloyNR-71.1189hoursforrupture
Vickers
hardness
466.
of specimens
of recisionFigure3 (a-toc).- Microstructures
castalloysNR-71(X-40),
NR-87YCo-Cr-Ni
base- 5M0,5W)aftercomplebase- 9Mo),andNR-90(Oo-Cr-Ni
acid etch.
Electrolytic
chromic
tionof 13500F rupture
test.
●
.
.
.
NACA TN
No.
19
1380
-,
.*
Fracture,
100X
Interior,1000X
(b) AlloyNR-87.1980hoursfor ruptureunder34,000psi;
Vickershardness
412.
Figure3.-Continued.
.
.
.
.
.
.
NACA TN
No.
21
1380
Fracture,
100X
.
-“4
Interior,
1000X
(c) AlloyNR-90.1630 hours for ruptureunder 32,500Rsi;
Vickershardness405.
Figure3.- concluded~
—
.
.
.
“
.
NR-71.,
Rupturestrenuth Referenoefor
100 hr 1000 hr dataabove1350°1
Alloy
2
WroughtNR-82 c1
m
Wr.,,
vhk NR-R4
,.
WN3t-m-71
I1A
-.
.— . .
:aB,NM+,
Cast NR-90
NR-90”
-v-%-.
!
4
a
*
@
.
.
;$b
\
E
5 20.00
.-.,=
A
2
A
,
-,
o
II
●
11,2,
1
---
v
I
:
I
Q
6and4
2
I
I
7
\
,.\
-.
.
}
\
\
>
.
‘. .
\
NATIONALADVISORYCOMMITTEE
Ji’OR
AERONAUTICS
I
I
.&
\
1500
1700
1600
Temperature,
‘F
10,
1;00
1400
1800
1900
2000
for wrought .
l?igure
4.- Variation of rupture etrengths with temperature
alloysNR-82and NR-84and caetalloysNR-71,NR-87and X?R-90.
t