Swelling in several commercial alloys irradiated to very high neutron fluence

201

Journal of Nuclear Materials 122 & 123 (1984) 207-213 North-Holland, Amsterdam

SWELLING

IN SEVERAL COMMERCIAL ALLOYS IRRADIATED TO VERY HIGH NEUTRON FLUENCE"

0. S. GELLES Westinghouse

Hanford Company,

Richland,

Washington

99352

Swelling values have been obtained from a set of commercial alloys irradiated in EBR-II to a peak fluence of 2.5 x 1023 n/cm2 (E > 0.1 MeV) or %125 dpa coverinq the range 400 to The alloys can be ranked for swelling resistance from highest to lowest as follows: 65O'C. martensitic and ferritic alloys, the zirconium based alloys, the precipitation strenathened and nickel based alloys, the molybdenum alloys and the austenitic allovs.

as 20°C lower for the highest temperature

1. INTRODUCTION Irradiation materials

induced swelling

property

affecting

Allowance

fusion reactor.

made when determining

is an important

the design of a

capsules

and

The compositions

of the specimens

is often found to be a limiting design

their heat treatments

factor.

As part of the National Cladding/Duct

Composition

Materials

Development

Program

(NCD) for Liquid

series of commercial

a

alloys were included

the AA-I swelling test and irradiations begun in December Breeder Reactor

(EBR) II, at Idaho Falls, ID.

Results of density change measurements specimens

were

1974, in the Experimental

examined

on

at earlier discharges

AA-I test have been reported

of the 192 previously.

Those specimens

Fusion materials ferritic

are reported

as E > 0.1 MeV) or

namely those

irradiation

iation temnerature

two temperatures,

at each irrad-

where available.

remainder were measured

425°C condition

a peak fluence of 2.53 x 1O23 n/cm2

community,

density followina

the final irradiation

(all fluences

in Table

nf major interest to the

alloys and refractory alloys which 2 examined, were measured for

corresponded

achieved

in Table 2.

by Lukens Steel Company

were previously

This paper reports results on specimens from of the AA-I test which

are provided

overchecks

are in qood agreement with the values 1.

in

examined

from the AA-I test are listed in Table 1 and

swelling

Metal Fast Breeder Reactor development,

sub-

less for the

remainder.

for swelling must be

design tolerances

and proportionately

the iron

The

after irradiation

at

425°C and 54O"C, because they

to hioh flux conditions.

The

was to identify materials

which

develop a swellina maximum

at low tempera-

tures.

was to provide data

The 540' condition

*125 dpa.

at a higher temperature,

2. EXPERIMENTAL

swelling temperature for AISI 316 stainless 3 steel. Details regarding density

PROCEDURE

Details of the AA1 test design and configuration have been documented previously. 192 The present effort concerns

The temperatures

as in references eratures.

procedures previously. 1,2

have been described

capsule 8116 fol-

lowing its removal from reactor for the fourth time.

measurement

close tn the peak

reported

1 and 2, are the design temp-

The actual temperatures

3. RESULTS

in this paper,

are as much

The swelling results are oresented 2.

and for the refractory

*Research sponsored by the Office of Fusion Energy, U. S. Department Number DE-AC06-76FF02170 with Westinghouse Electric Corporation

0022-3 115/84/$03.00 0 Elsevier Science Publishers (North-Holland Physics Publishing Division)

B.V.

in Table

Results for several of the ferritic

alloys

alloys which were

of Eneroy under Contract

Base

625*

Inconel

TZM

Nb-1Zr

Hastelloy C-4* Inconel 600*

X* S*

80A* 115*

Nimonic Nimonic

Hastelloy Hastelloy

901* 718* X-750*

Incoloy Inconel Inconel

+Includes

Ta.

1.31 2.02

7.81

co.005 0.003

0.73 0.45 8.03

18.8

4.36

0.17 0.48

co.002 0.001

International Corporation.

Nickel

0.003 0.013

__ __

bal.

16.6 15.3 15.8

0.09

Company,

-__

co.004 0.45

0142 0.25

is a registered

bal. __

0.21 0:;8

-__ __ __

__

__ 5.28+ l.Ob+ 00 __ 3.35

__

3.07 2,85 0.92 2.45 2.57 3.78 0.28

1.16 0.26 0.50 0.68 1.42 4.94 0.29

0144

__

1.2

1:

-__

__

Ti

2.20 2.38

0.38

__ __

00

5104

-__

__

Al Si

trademark

0.005 0.002

0.45 0.05 0.04 0.21

of

Cu = 0.04

Henry

Wiggin

Zr = 0.96, Zr = 0.09

Cu = 0.32

& Co.,

Ta = 0.095

W = 0.5, CO = 1.96 w = 0.07, co = 0.11

Zr = 0.04,

U.K.,

V = 0.25 Co = 0.020, Zr = 0.12 W = 4.03, Zr = 0.04 a = 0.16

0.54 1:;o 0.10 0.23 0.07 0.14 0.20 0.15

cu = 0.33 Cu = 0.25 cu = 0.54

V = 0.27 __ __ Y = 0.68 Cu = 2.14

v = 0.49

nther

0.56 1.27 0.45

Or08

0.88 0.28 0.48 0.50

(weight percent)

0.17 1.59

__ __ __

---

0.24+

__

0.40 __-

__

Nb ---

Nimonic

0.24

0.46 0.21 --

0.09

0.03 0.03

0.002~0.002 bal. --

__

8.84 15.3 14.3

0.11 0.006 0.002 0.08

21.2

9.17

3.23

00

0.10 0.10

0:;o

1.22

0.91

1.52 1.58

o:;o

0.37 1.00 0.42 0.40

Mn

BY THE VENDORS

0.02

0.07 0.16

0.045

bal. bal.

19.5 14.5 21.9

15.4

bal.

bal.

bal. bal. bal.

5.50 2.83

0.04 0.04 0.04

13.7 18.6

0.05 0.34

14.2 18.35 14.9

42.2 bal.

4.15

0.07

20.5

33.7 24.6 34.1 44.8

bal. bal. bal. bal. 18.5

1.21 4.26

0.05

0.30 __ __

0.06

19.1

_-

0.26 0.04 __

24.7

0.42 0.09 0.11 0.04 0.009 0.008

4.97 9.42 13.36 17.64 22.5 11.7

--MO

19.7 36.05

C

--Cr

AS SUPPLIED

1

bal. bal. bal.

*Incoloy and Inconel are registered trademarks of the and Hastelloy is a registered trademark of the Cabot

Refractory

Nickel

A286

Precipitation Strengthened

Ma13 0979

AISI 310 RA-330 Incoloy 800*

8.4

_-

bal. bal.

FeCrAlY Carpenter 455

0127 __

Custom

0.12

bal. bal. bal.

Ni

bal.

Fe

OF THE ALLOYS

AISI 416 430 F

Hll EM-12

Alloy

Austenitic

Ferritic

Type

COMPOSITIONS

TABLE

Heat Treatment 0.14 0.56 0.25 0.20 0.12 -0.36 49.79 12.36 41.08 31.60 N.M. 1.75 -1.91 0.15 0.60 1.06 4.18 1.47 1.16 2.05 1.01 -2.30 -0.30 -0.09 12.70 7.92 0.53 0.03

0.16 0.57 0.35 0.23

0.25 0.03

0.18 -0.02 0.08 0.09

450 1.55 -_----0.05 -0.38 0.20 0.24

0.43 0.36

-0.11 -0.28 0.08 0.17

0.16 0.02

0.04 -0.29 0.05 0.05 -0.18 1.78 17.92 2.04 11.95 0.51 0.81 1.84 -2.45 -0.07 0.25 -0.06 0.46 -0.05 0.33 7.17 -0.06 38.00 0.06 4.79 1.60 0.07 0.31 0.05

Swelling (AV/Vo, %) 480 510 540 2.41 2.32 1.98

0.39 3.77

79.90

590 2.53

0.56 2.86

0.C18 0.2'1 0.1 1

656 2.50

Heat Treatment Code: temperature ("C)/time (hour)/W. Q. = water quench, A.C. = air cooled, F.C. = furnace cool, O.Q. = oil quench, V.C. = cool under vacuum.

0.43 0.35

425 2.07

400 1.60

Temperature ("C) Fluence (1023n/cm2)

IN 8116 OF THE AA-I TEST

IRRADIATED

FOR SPECIMENS

MEASUREMENTS

lOlO/l/W.Q.+5iO/2/W.Q. 1050/0.5/A.C.+750/1.5/A.C. 87O/F.C. AT 13'C Per Hour to 590/A.C. 107O/l/W.Q. Consolidated at 1150°C 107O/l/W.Q. + 510/4/A.C. 1070/1/w.q. 107O/l/W.Q. 107O/l/W.Q. 107O/l/W.Q. 980/1/O.Q. + 720/16/A.C. 1080/4/A.C. + 900/1/A.C. + 750/8/A.C. 1020/2/W.Q. + 840/6/A.C. + 705/16/A.C. 1100/3/W.Q. + 790/4/A.C. + 720/24/A.C. 75O/l/W.Q. + 720/8/F.C. to 620/18 total A.C. 1150/2/A.C. INC. X-750 1150/2/A.C. + 840/24/A.C. + 700/20/A.C. INC. X-750 1150/2/A.C. + 840/0.5/A.C. NIM. 80A 1080/8/A.C. + 705/16/A.C. NlM115 1190/1.5/A.C. + 1100/6/A.C. INC 625 115O/l/W.Q. HAST X 1190/1/W.Q. HAST S 1070/1/A.C. HAST C-4 1070/1.5/W.Q. 1120/1.5/A.C. INC 600 20% cold worked INC 600 1200/1/v.c. Nb-1Zr TZM 1300/2.5/V.C.

Hll EM12 AISI 416 430 F FeCrAlY C.C. 455 AISI 310 RA-330 INC. 800 A-286 A-286 M813 0979 INC. 901 INC. 718 INC. X-750

Alloy

SWELLING

TABLE 2

210

D.S. Gelles / Swelling in several commercial alloys

measured

over the full range of irradiation

temperature swelling

show that these materials

alloys.

Only TZM developed

in excess of 1%.

are low swelling

Results for the remaining

was very swellinq resistant

at low

temperatures,

moderate

but developed

1.78% at 540°C.

swellinq,

As this alloy contains

10% nickel which promotes

austenite

almost

and as it

alloys indicate that most of the alloys

is uncharacteristic

investigated

swell at 54O"C, the observed

hiqh temperature

response could be attrjbuted

to swelling

are low swelling,

notable exceptions 3.1.

but several

occur.

Ferritic/Martensitic

Hll is a corrosion martensitic

Alloys

resistant

5% chromium

the ferritic/ commercial

applications.

It is found to be highly swell-

resistant.

ing resistant,

with peak swelling of 0.18% for

fluence4

this magnitude

condition.

generally

Values of

arise from precipit-

ation rather than void development. French heat exchanger

material

(ferrite and martensite)

EM-12 is a

with a duplex

microstructure.

density change measurements

alloys to

austenite which forms in-reactor.

steel used in heat exchanger

the 45O'C irradiation

for ferritic

The

show peak swelling

of 0.6% at 400 to 425'C and densification

on

martensitic

in

In summarv,

allov class nf

alloys apnears to be hiqhly swellinn Even when voids develop

at a low

, the swellinq rate remains very tow. Austenitic

3.2.

Alloys

AISJ 310 stainless treated condition

steel in the solution

was expected to show hiqh

swellina.

It swelled 49.8% at 425'C and 17.qX

at 54O'C.

R.A. 330 stainless

solution treated condition

steel in the

also swelled, but

the swelling was not as larqe.

It swelled

the order of -0.10 to -0.30% for the temp-

12.4% at 425°C and 2.04% at 54O'C.

erature

800, an alloy vet-y similar to RA 330, hut with

range 480 to 540°C.

These results are

minor aluminum

very similar to those found for lower fluences'

Such a response was

stainless 540°c.

The Alloy AISI 416, a

not expecteds4

stainless

steel with low

therefore

molybdenum,

is also highly swelling resistant.

swellino

resufts,2

in comparison minor

Therefore,

it is possible

that AISI 416 begins to swell at fluences

on

the order of 90 dpa.

The alloy 43OF, which

contains

and is fully ferritic,

17% chromium

was developed

for corrosion

very swelling

resistant

resistance.

It is

stainless

alloys in this test.

temperature swelling

310

steels are

found to be some of the highest

systematically

with lower fluence

increases of 0.1% are found

for 400 and 425°C.

and lower

steel, 41% at 425°C and 11.9% at

Austenitic

martensitic

However,

additions

silicon swelled about the same as AISI

and indicate this alloy may be

stable at high fluences.

and titanium

Incolov

Swellinq

is

hipher at the lower irradiation

and additions of silicon reduce

at both temperatures. Precipitation

3.3.

Alloy A-286 precipitation

Strenothened

Alloys

is a pamma prime (Ni3(Al,Ti)) strengthened

nickel composition

ranqe.

alloy in the 76% Followinq

irra-

and gives results very 2 similar to those found at a lower fluence.

diation

The alloy FeCrAlY

whereas

at 54O"C, swelling was negligible

0.51%.

The high swellinq

fully ferritic temperature

is an yttria strengthened

alloy which provides high

corrosion

like other ferritic/

resistance. martensitic

very swelling resistant. is a martensitic strengthened

It behaves alloys and is

Carpenter

Custom 455

of copper.

condition

attributed

It

tieveloped hiah swelling,

to a chanqe

Gamma prime transformed

31.6%, at

at 425°C can be

in precipitate

phase.

to eta (Ni3Ti) in the

form of larpe thin sheets in this condition followinq

alloy designed to be

by precipitation

at 425"C, the solution treated

low fluence neutron

irradiation

425°C (R. W. Powell of Westinghouse

at

Hanford

211

D.S. Gelles / Swelling in several commercial alloys

Company,

private communication.)

observation

is reported

Unfortunately,

for the aged condition5.

the 425“C condition

A-286 was not available, A-286 developed

negligible

in the 35% nickel range.

alloy provides

alloy moderate

nickel content of 42%, with a high titanium

4%.

Its swelling

0979 densified irradiation

response

to of

is quite different.

approximately

given this

size distribution

particle

with the largest particles

being on the order of one micron be behaving

in size. as had an

The final

in reactor.

alloy in the precipitation

strengthened

prime strenqthened

alloy.

The swelling

for

of X-750 and Nimonic 80A.

In summary,

iron and

strenqthened

Incoloy 901 is very similar to D979 but has an

superalloys

are qenerally

low swelling

even higher titanium

to aluminum ratio and no

materials.

The exceptions

It is a very low swelling

situation where a phase change promoted

tungsten

is not yet available.

additions.

contains

alloy.

It

53% nickel and uses a 5% addition of

niobium to promote the gamma double prime phase The consequence

(Ni3Nb) for strength. swelling,

0.60%,

swelling,

0.25%, at 54O“C.

conditions irradiation

condition

and -0.05% for the other two.

X-750, develops Nimonic

For

is low, 0.46% for the overaqed

Nimonic 80A, an alloy similar

X is a high-temperature

alloy with ~20% chromium

Hastelloy

X densified,

in composition

to

from Nimonic 80A primarily

Hastelloy

C-4 a similar alloy qave intermediate Inconel 600, an alloy intermediate

composition

between Hastelloy

or C-4 but without

more swelling, 540°c.

Nimonic

to

additions.

result in significantly

2.96% at 42O'C and 6.69% at 115 therefore

swells higher at

molybdenum

in

X and Hastelloy and with minor

of qamma prime forming elements,

developed moderate

swelling.

A value of 12.7%

swelling was found for 54O'C in solution annealed

Inconel 600.

and 0.07% swelling

However, these changes

The

Hastelloy

gamma prime precipitate,

ratio and 3% molybdenum

S, an alloy with

results.

cold worked,

aluminum

-2.36% at 425Y

iron and higher levels of molybdenum

as a result of a higher volume fraction of a lower titanium

corrosion and 20%

and swelled 38.0% at 54O'C and 79.9% at 59O'C.

additions

swelling of similar magnitude.

115 differs

resistant

swelling was -0.30% at 425°C and 0.06% at 540°C.

at 54O"C, the same behavior occurs

but the swelling

swelling developed.

and nickel, was highly swelling resistant.

and the aged

condition.

a

high

Nickel Base Alloys

Hastelloy

In comparison,

but develops 4% under identical in the overaged

3.4.

negligible

1% swelling at 425'C

in both the solution treated conditions,

alloy

in three heat treatment

It develops

was used and moderate

iron.

Inconel X-750 is a

nickel base gamma prime strengthened

conditions.

is low

at 425°C and negligible

which was irradiated

either involved

swelling or where an overaged microstructure

alloy, 0.15% at 425"C, -0.07% at 540°C. Inconel 718 is a somewhat different

series

was Inconel 625, a nickel base gamma double

nickel base precipitation

the densification

The

response of Inconel 625 was similar to that

2% at both An explanation

temperatures.

The heat treatment

overaged microstructure

additions

A possible

a triplex precipitate

alloy may therefore

1.72% at 425“C and 1.81% at 540°C.

0979 is similar to M813 but with a hiqher

aluminum ratio and with tungsten

temperature.

for the hiaher swellina response

microstructure.

swelling, 0.81%.

It developed

explanation

can be ascribed to the preirradiation

for aged

but at 54O"C, aged

M813 is also a gamma prime strengthened

swelling,

the higher irradiation

A similar

developed

Inconel 600, in the 20% 7.92% swelling

at 54O'C.

nickel based solid solution hardened developed

at 425°C

In summary, alloys

a wide range of swelling responses.

Low swelling, moderate

swellinq and high

swelling alloys were found and the temperature

S

212

D.S. Gelles / Swelling in several commercial alloys

dependence

of swelling

varied from peak

swelling at low temperatures

dpa.

to peak swelling

at high temperatures. 3.5.

Refractory

Alloys

used for high temperature

range studied Comparison

the refractory

commercial

applications.

another: 0.6% for Nb-1Zr versus 3.6% for TZM.

It is over the

in swelling

saturation

with lower fluence

therefore

at doses on the order of 75 doa and further

strengthened

in this alloy has saturated.

alloy used for high temperature

available

applications.

temperature

peak swelling of 3.77% measured

swelling

cubic

swelling over the

range of irradiation

irradiation

TZM is a

base body centered

It develops moderate

condition.

with

for the 590°C

This represents

a low

rate' .OOZ% per dpa, and indicates

that swelling

in this alloy is approachinq A similar comparison

saturation.

case shows that TZM is densifying A specimen

fluence.

based on lower fluence justified.

In summary,

alloys are moderately resistant

examined

at fluence

cannot be

refractory

commerical

at

in both alloys

three classes of

alloys which remain either low swell-

high fluence.

swelling

(<5%) at

Ferritic/Martensitic

alloys are

found to be the most swelling resistant group of alloys.

influenced

as a

Apart from the case where

austenite formation behavior,

is expected swelling

to have

remains well

below 1% and the highest swelling alloy maintains

a very low swelling

However,

saturation

cannot be

qenerally

demonstrated

therefore

hiqher swelling can be anticipated

in this alloy class and at

still higher doses. Comparison

4.2.

The swelling

With Simple Alloys

response

in simple alloys can

provide a basis for rtnderstandinq the swelling

rate:

Simple ferritic

alloys develop

void swelling only at irradiation below 500°C in fast reactors, temperature

temperatures

the peak swellinp

is 425"C, and the swellinq rate

which is obtained

is low compared to simple

alloys.7

Such results are in qood

agreement with the present results except that in the present case several alloys do not

fluence,

and when they do, the swelling rates

obtained

are not as larae as in simple alloys.

It can therefore

The Low Swelling Alloy Classes

ing (~1%) or moderate

is involved.

or overaqinq

appear to develop void swellinq even at high

levels of 100 dpa.

The present work identifies commercial

swellinq except in the exceptional

cases where a phase transformation

austenitic

4. DISCUSSION 4.1.

alloys are also found to be low or

behavior found in the present study on commer-

to highly swelling

is apparent

are not

Precipitation

cial alloys.

with peak swelling occurring

Saturation

in swelling

at hiqh

but predictions

response6

moderate

increases

at even hiqher doses.

for the 630°C

to specimen variation

might explain the difference

590=X.

and that

level from one alloy to

The alloy class appears to develop swelling

in the experiment,

in the data occurs at higher fluence

molybdenum

alloy class of

alloys does develop siqnificant

expected

swelling

alloys are less

differences

data2 appears to show that a larger scatter

commercial

refractorv

but still low swellino.

niobium base alloy

found to be highly swelling resistant

400 to 630°C.

swelling resistant However,

NB-1Zr is a commercial

temperature

In comparison,

0.01% per

be concluded

the swellinq

behavior of the ferritic/martensitic alloys may be overpredicted

commercial

by simple alloy

response.

Minor element additions

increase

incubation

period prior to swelling and may

the

reduce the steady state swelling rate. Austenitic

alloy swelling response can also

be successfully behavior.

predicted

In Fe-Cr-Ni

by simple alloy

pure ternary alloys

R,9

swelling rates of 1% per dpa are independent chromium

of

and/or nickel content for alloys with

213

D.S. Gelles / Swelling in several commercial alloys

However,

35% nickel or less. the transient increasing

regime of swelling

nickel or temperature

with chromium swelling

the duration

content.

is therefore

of

increases with and decreases

Higher accumulated

The results

found at 425°C than at

nickel , "lo

similar . response

except that a peak swelling

The present trends.

ceptions

is obtained

element

rate is difficult

to define due to the large transient

regime.

at 425°C estimated

with the irradiations

incubation

peak swelling

fluence.

in commercial

Therefore,

alloys.

alloys, swelling

data.

Nimonic

An explanation

not yet available.

in

exist how-

for these exceptions

Finally,

it is possible

itic and precipitation

strengthened

low or moderate

S

controlled

is to

of those austen-

swelling

alloys which

as having swel-

by a very high swel-

fluence.

5. CONCLUSIONS A series of 24 commercial

alloys covering

a

wide range of alloy types has been examined following

irradiation

high as 125 dpa.

these alloy classes rated as follows:

in EBR-II to fluences

The swelling

Those

are J. F. Bates, J. S. Pintler

change measurements

and his

are also acknowledged.

REFERENCES

is found

X and Hastelloy

response

ling responses

alloys

more at 540°C than at

interpret the swelling

ling incubation

contributions

in the AA1 test.

recogniation

and D. T. Peterson.

made the density

the

is very clear

115, Hastelloy

special

R. R. Borisch

is higher at 425

Three exceptions

each swell significantly

develop

can play

of swelling.

In most

or high swelling

than at 54O"C, a trend which

425°C.

a low estimate

rate in these commercial

that of ternary

cases where moderate

ever.

deserving

it assumes 4.0 x 1O22 n/cm2 for the

the ternary

and microstructure

role in the control

A great many people have been involved

using the present data and

This is probably

0.6% per dpa.

approaches

additions

that minor

ACKNOWLEDGMENTS

rate for AISI 310

data' at 4.3 x 1O22 n/cm2 can be shown to be

swelling

of simple alloys but many ex-

are found which demonstrate

an important

based

results follow several of these

The peak swelling

because

tend to follow predictions

on the response

For alloys with greater than 35%

540°c.

Ferritic/Martensitic Alloys Refractory Alloys Precipitation Strengthened Superalloys Nickel Base Alloys Austenitic Stainless Steels

resistance

as

of

(from best to worst) may be

1. J.F. Bates and R.W. Powell, J. Nut. Mat. 102 (1981) 200. 2. R.W. Powell, D.T. Peterson, M.I. Zimmerscheid and J.F. Bates, Ibid, 103 & 104 (1981) 969. 3. J.F. Bates and M.K. Korenko, (1980) 303. 4. D.S. Gelles, 975.

Nut. Tech. 48

J. Nut. Mat. 103 & 104, (1981)

5. D.S. Gelles, L.E. Thomas and J.J. Laidler, J. Nut. Mat. 108 & 109 (1982) 504. 6. D.S. Gelles, D.T. Peterson and J.F. Bates, J. Nut. Mat. 103 & 104 (1981) 1141. 7. D.S. Gelles and L.E. Thomas, HEDL-SA-2772FP, to be published in the Proceedings of the AIME Topical Conference on Ferritic Alloys for Use in Nuclear Energy Technolog;es. a. F.A. Garner, Damage Analysis and Fundamental Studies Quarterly Progress Report, DOE/ER-0046/14 (July 1983) 133. 9. F. A. Garner, 10. H.R. Brager

these proceedings.

and F.A. Garner,

Ibid 152.