Oscillation of phase transitions and atomic ordering in carbon martensite

Scripta METALLURGICA e t MATERIALIA

Vol.

29, pp. 1509-1512, 1993 Printed in the U.S.A.

OSCILLATION OF PHASE TRANSITIONS

Pergamon Press Ltd. All rights reserved

AND A'FuMIC ORDERINb iN CARBON

MARTENSITE

L.

Dabrowski

,

J.

Suwalskl

*.

Institute

of

~.

Institute

for

AtomLc

T.

shose

05-400

Research Sofia

72,

V.

CbF~stov

.

Surdzh~ I s k l

Energy,

Nuclear

Tsarlgradsko

5idzhlmow

B

V.

Otwock

and

Swlerk,

Nuclear

Poland

Enerqv,

bivd_

Butgarla

1784,

( R e c e i v e d J u l y 16, 1993) (Revised September 3, 1993) I . The

~ ~ x martensite

carbon content temperature

which in

has

differ

the

that

this of

observed

to

found

transition

in the

region of

first

close

in

be

of

of

the

have

been

and

in the

alloys

the

other

obtained

hand,

interstitial According

martensite, with

on

the

consideration

of

the

conclusion

that

the

decrease

and

monotonous. the

of

or

the

the

occurring

same

its

we

time,

as

parameter to

correlated

there the

is those

character

[3]

body

of

the

They

were

has

been

that

in the

while

[4]

it

in the

is

region

the

type

still

being

order

in the

are

expected

to

This

interaction

the

as

the

ordering

1509 0956-716X/93 $ 6 . 0 0 + .00 Copyright (c) 1993 P e r g a m o n P r e s s

of

model

C-C.

The

of

the

to

the

a system

and

coherence leads

~ - phase

investigations

transition

be

has

in s u c h

in the

case

result

austenite,

transition

-

actively

[5,6],

theoretical phase

It

order,

of are

as well to

time.

Fe-Ni

hysteresis.

[7],

the

long

studies

transitions

two

solid

of A3B.

theoretical

is no p h a s e

of

and

in

stoichiometric

established

solutions

degree

a

second

solid

the

type

order.

transitions

compared

Thus,

[2]

is of

Cu-Au

latter as

for

phase

to

of

disorder

second

content

these

basis

lattice,

explain

in

particular,

substituted

studied

a considerable

martensite

-

in

transition

On

order,

At

strictly

theoretically

this

stoichiometric

in

In

in time.

Z

features,

processes

decreases,

order

first

the

carbon

first

[I]

order

of

the

of C u Z n ,

investigated.

wt

diffraction

analogical

particular,

to

disorder

0.87

characteristic

established.

oscillations,

and

× - phase.

experimentally -

from

I .I

x-ray

Some

ordering

transitions

of m e t a l s ,

to

w~th

by

K-

oscillates

atomic

and,

solutions

350

have been

analogical

Phase solutions

to

transltion

the

trans~tlon

studied

300

alloys,

degree

subjected

of

this

substituted

show

been

range

Introduct. lon

phase

in

Ltd.

is

been

gradual did

not

martensite.

So

1510

ORDERING

far,

this

problem

experimental

has

not

been

investigations,

from the c h a r a c t e r we p r e s e n t

of

a more

IN M A R T E N S I T E

the

subjected

either.

phase

detailed

Vol.

to

In the p r e s e n t

transition

investigation

in

29,

systematic

paper,

carbon

apart

martensite,

of the k i n e t i c s

in

this

prepared.

The

region. 2..:.._~.~P.~..~..~.~ Two carbon

samples

concentration

quenching

left a g i n g

doublet

Starting step

by

given

peaks

from r o o m step

to

lasting

parameter

From

content

of

the

values

a simple

t

The

is

calculated

by

means

content,

formed

the I

shown

× -phase

tetragonal

regime,

allow

range

it

K.

out At

a

( each

the and

of

lattice

the

I

:

lattice

(

the

the

time.

ordering the

~

(U33-

solution

was

phase

each

of

the

of

the

of

the

regime

From

decreases

decrease

the

These

q.

-

values

shows

as

ten-

parameter

for

t.

temperature

not

of

~ ~

the

Th e

t

I

l)/n Jn

which,

for

figure.

oscillations

-

parameter

[5],

above

same

increases

c/a

in

ordering

fig.

in

concentration-expansion to

results

does

ordering

given

given

the

the

20

concentration the

with

fig.

I,

with

it

the

monotonouslv,

that

content

the

temperature

but of

the

rises,

oscillations

are

ordering

parameter

the

is rise

and

strictly X

in

~ -phase. 4.

X-ray

long

parameter

Moreover.

in

the

with

of

of

carried

10 -

determine

formula

method

on

were

martensite

yields:

shows

parameter

oscillates

correlated

of

time.

the

proportional

however,

in

similarly

the

the

temperature;

newly

c,

ordering

The

parameters.

measurements

to

After

nitrogen

phase.

carbon

together

are

that

oscillates

is

lattice

AT = of

wt %.

liquid

temperature.

the

with

~ -

the

components

Figure

measurements,

of

are

range

measurements.

obvious

x -

of

0.87

in

room

order

a and

and

the m e a s u r e m e n t s

in

atomic

parameter long

phase

of

means

the

Ull

at

determine

tetragonal the

1.1,

a series

transformation,

n

and

The

)

and

where

to

were

immersed

months

used

min

by

was

temperatures,

the

after

a n d U33

four

thick

were

temperature,

35 c

calculated

sor.

for

of

UI1) ,

samples

samples

we p e r f o r m e d

for

a and

q was

the

50 /Jm

the

higher

constants

ARNCO,

were

temperature,

them

x -

of

in w a t e r ,

and then (llO)

of p u r e

measurements, us

to

observe

Discusslon-

combined some

with

interesting

a

time features

-

temperature of

the

phase

No.

ii

Vol.

29, No,

Ii

ORDERING

transition

in

martensite.

feature

as t h e of

this

first

long

range

Iike

to

problem w~th

~nterst

itial

the

in

is

the

Fe-Ni

decreases

characteristic

we

of

of

Cu-Au,

parameter

transitions,

solid

for

observed

oscillations

decreases ion

and

of

I

or

Furthermore,

in

by

any

theoretical

work

and

For

cannot or

be

any of

we

from

of

this

of

the

this

type

takes

place

in

in

the

the as

transitions

Research

phase a

phase

known

, J.Als-Nielsen,

P h y s . R e v B,

Programme KBN No 2

,

(b)

2.

L.D~browsk

3.

N.S.Golosov,A.M.Tolstic,

4.

J.K.van

5.

G.V.Kurdiumov,A.G.Khachaturyan,Acta Met.,23

6.

L.b~brow~ki,

7.

A.G.Khachaturyan, G.A.Shatalov,

(1976)

Phys.Stat.Sol.

128

2 (1970)

(1975)

277.

371.

J.Phys.Chem.Solids,

36

(1975)

899,

273. Deen,F.van

der

J.Mat.Sci.,25

Woudeo

Acre

(1990)

Metall

.,29

so

been p r e d i c t e d

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a

the

approache.

was s p o n s o r e d by

an

oscillations

either

not

in

fixed

reason,

have

would

in

ordering

recognized

the

analogical is

content

degree

of

ordering

feature whlch

which

those

the

differ

transition,

the

to

2437.

37

a

time

x -phase,

conclusion,

main

oscillates.

11 order"

new

conslderable

addition,

transltions

a

IV

The

with

~ ~ y martensite

transltion

Thls

In

As

essential

~ ~ × phase

the

correlated

transition

al Iovs.

interval

new × - p h a s e .

transit

phase

solution

the

of

strictly ~ -phase.

the

~n s u b s t i t u t e d

-phase

formation

the

that

temperature

vet

is

parameter

temperature

as

which

amplitudes

osc~ I lations

emphasize

processes

far.

Dhase

-phase

solutions

ordering

rises,

large

~

parameter_

occurs

the

wlth

solid

range

order

combined

also

of

long

1511

tetragonal

substituted

the

temperature

the

Another

wide

the

where

reduction, of

disintegrating

Unlike

and Cu-Zn, smoothly

the

IN M A R T E N S I T E

(1981) (1975)

1255. 1077.

2722. F l z . H e t . M e t . ( U S R R ) 3 2 (1971)

1512

ORDERING

Fig.

I.

Time

dependence

phase

the

k parameter

Vol.

l&)

and

of

content

(o).

1.2

r<

of

IN M A R T E N S I T E

I I

I I

I I

n

1.0

.87

=

w ~

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I

I

C

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I

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315K

3~5K

330K

1340K; 860K f

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1

>< 0.2

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I I

I

0.0

i

2

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i

10

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112

I I I

i

i

118

i

ll4

1'6

2(3

,

= 1.1 w ¢o

22

1.0

, ,' '

r<

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'

~C

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340K

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TIME

;

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(h)

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Y

29,

No.

11