Effect of microstructure on fatigue crack growth in Zr-2.5Nb alloy

84

Fatigue

of the material

and influence

In the present content

work

on stage

room

II

FCGR

temeprature

the fatigue

the effect

crack

of temper

of a martensitic

using

compact

growth

behaviour

embrittlement stainless

tension

of the steels.

and residual steel

specimens.

hydrogen

has been

Graphs.

studied

numerical

at

data,

Asbstracts inside

surface

analysis 500 to

MWe

3%

The

Fast

Breeder

mechanisms quick

Test

(CRDM)

shut down

barriers

for

gripper

control

expected

when

for

tested

to confirm

during

its operational

fuel

Intent

a

of

period

ten

the creep-fatigue the detailed

testing

test set up for bellows Graphs,

generated for

ambient

at multiple

single

(for

relation, values

reasonably

is

and is aimed determined

I Al

proposed.

R-dependencies

successful

and 2219-T85

stage fatigue

for

least

growth

to be

in

numerical

which

the

815 K Model’

indicates

The advantage

(FCC)

of an FCC

data

relation involves

parameters

in the adjustable

proposed

equation

material,

are

3 I6

high

strength,

standing

light

weight,

exhibit

superalloys.

environment.

great

potential

In this study,

processed,

near-infinity

understand

the

interactions.

fatigue

the

high

to differentiate

dependent

crack

behaviour

in

the

form

>

1.0 Hz

of

superimposed 0.01~2Cil

upon

SS

In order low have

been

hold 7x

effects

and increased effects

with

a retardation

creep

under

indicated

loading

resulting

maximum

growth

closure

effect

by

crack

load,

whereas rates.

Graphs,

at

to

blunting that

minimum

due

photomicrographs,

at

the environmental of

closure

model

to fatigue,

ha\ creep

22 ref.

influence

(FCC)

of

microstructures, received II

microstructure

rate in Zr-2.5

was

namely

pressure found

to

FCG

a-grains

behaviour

tube material

were

be insensitive

to

of the existing

have

room

better

models.

selected

Graph\,

sensitive.

for

studied numerical

01 +

crack

On

FCG

FCG.

a\

rate in stage

the other

has been rationalized data,

and

hand,

Microstructure

near threshold

growth

Four different

P-annealed

for the study.

microstructures.

resistance

fatigue

was investigated.

S-annealed,

microstructure

of microstructures

temperature

tube material

P-quenched,

rate in stage I was strongly ahgned

on

Nb pressure

FCG

containing The

observed

with

the help

photomicrographs,

9 ref.

Fatigue crack growth studies on primary heat transport piping. Chattopodhyny, J., Duttci, B. K. and Kushwho. H.S. Trmsnctions of the Indian Institute cf M&r/s ( 1996) 49, 5277532 The

leak-before-break

primary levels

heat transport of

performs

LBB

analysis.

fatigue

crack

(LBB)

concept

(PHT)

piping

The growth

present study

is now

universally

of nuclear paper

power

deals

of a postulated

used

plants.

with

the

to design

There level

part-through

the

are three two

flaw

total

imposing

the

(n PFBR analysis’

outlet

wrth

‘Reduced

becauw

elastx

perof

Chnboch I\

. X25 K.

of performing

analysi\,

SS 3lhLN.

rules

hy

tempemturc

of this component

simple

in

inelastic

demonstrated

temperature,

Material:

axral

rewlts

Graph\,

\ignifcant

at

in an

numerical

at low

the

strain

pre-exposed under

mode

ranges

of

IO

and

I and

duratrons

tested

in wdium

condition\.

fatigue

in sodium

prior

range.

Graphs,

LCF

lives

rn hoth

using

a

conduc-

peak

tensile

found

to

for te\ts

the environments to he beneficial

Thi\

data.

were rate 01

and

Mere

proved

studied.

numerical

strain

at

and

tc\t\

of . 4. However.

to te\ting

ranges

tu 3000 h)

tests were

30 min

on

studic\

cycling

1.59,

interaction

in air up to by a factor

strain

(up

continuou\ The

time

steel.

at a constant

0.6,

of specunens

three

and hold

stainless

rn air cnvn-onment\.

of

live\

time

all

sodium

Creep-fatigue

holds

Exposure

life

and

form.

than those tested

fatigue

and

pre-agmg

316L(N)

conducted

strain

wave

hold

sodium. type

strain-controlled

total

fatigue

under

of liqurd

tests were

temion

comparable.

effect

vvds more

22 rel

Influence of prior thermal aging on creep and low cycle fatigue behaviour of forged thick section 9Cr-1Mo ferritic sheet at 793 K. Choud%ory. R.K.. Vr~vrnnmi. A., Smkrrm Rae. K.B.. Momm. Xl. mrrl Km/v JU/J, B. P. Trmcrrc~tionv of t/w Irrdim Iu\titrrtr of Mrtol\ CI YY6) 49. I7Y-48X Detailed prior

mvestigations

thermal

aging

9CrrI

thermally

LCF

793 K.

signiticant

granular LCF to

matertal

softening

particle

r&stance in atre\s

which on the

aged

intensity

tip

of

mode

under

m

mode\

obeying

aged material

has been ascrrhed mam

compared progressive

remained

cracking.

exten-

improved

mainly

crack

power-lau transgrunulnr

exhibited

The

LCF

to the reduction

caused

Photomicropraphs.

trans-

test condnrom

exhibited

thermally

cracks.

at

observed

rcmumed

all

behaciour

and

continw

\pccimens

to he higher

secondary

propagating

and xxondary

wa\

found

stress-strain

aged material

and TA

materials

and propagation higher

in quenched

controlled

failure

01

of thick

(SPWHT)

propertre\

wa\ TA

~nlluence

conducted

on SPWHT The

and

the

behaviour

treatment

coalewxrce

However, and

at the

decohesion

(ICF)

heat

rupture

material

cyclic

conditions.

decohesion

void

SPWHT

initiation

of thermally

particlc

performed

by

and similar

in both material sive

tests were

weld

investigated.

Both

The crack

Creep

m creep

conditions

of thermally

to understand

fatigue

post

variation

maternal.

out

cycle

at 793 K. Total-axral-strain

characterized

resistance

cyclic

simulated

tests have been

ductile

SPWHT

carried

and low

condrtiom

ous cycling the three

been

steel forging.

(Q + T),

aged (TA) No

have

on creep

MO ferritic

tempered

data.

Effect of microstructure on fatigue crack growth in Zr-2SNb alloy. Guncu!\‘, S., Dubey, J.S., Hay, A., Chnkrmortty, J.K.. Biswm. A.R. rrrrd Banerjre, S. Trnnstrctions of the Indian lnstitutr of Mernls(1996) 49, 5X-540 The

of

of modified

in sodium

triangular

relationship.

loads,

crack

superposition

interactions

trme

produced

be attributed

to enhance

A linear

the complex

hold

01.

crack

as a consequence

hold

appear

the

It is believed

of

blunting for

loads

range

of

under

be higher

section

crack-tip

in this material.

due to crack-tip

degradation.

might

in an interaction

growth

for

whrch

analy&

outlet

on aweceived The

conditions

In general.

and

frequency

degradation,

of

contidcnce

detailed

‘elastic

it i\

that reactor

temperature

1%.

the inHuence bchav,iour

IO 1s ‘/ employing

was used

a wide of

model

instead -

Whde

of. _ 770 K,

a viscoplatic

of

component

rules of RCCMR.

performed.

ORNL

analysis

conducted

time

technique

minimum

dependence

Superposition

and micro-cracking

to account

over

loading

and time-

testing

and

I .O Hz cyclic

rate,

level

results

applied

in lower

and ewironmental

strong

frequency.

of

intermetallics

performed a

range

A novel

maximum

environmental

load

crack-branching

employed

at

p-

analyzed

the cycle-dependent

aluminide

Experiments

asperity-induced

loads

times

in crack

at maximum

been

hold

of enhanced

time

extensive

titanium

and

nickel-base

has been

a wide

two

with-

alloys

cree~fatigueeenvironment

of this material.

loads over a baseline

variation

the combined

between

with

Further

at X23 K.

symmetrical

to

of an advanced

at 866 K

been

temperature

efficiency

fatigue

specimens

were

of safety

traditional

is found

perwd

the lwel

the most critical

that the permissible

to a\\ess

cycle

conducted

demand

titanium

behaviour

IO0

temperature

for

Hz

cyclic

and minimum

an insignificant

a hold

frequency.

from

rate

maximum

by the author

baseline

frequencies growth

growth

for

investigation,

was employed

employed

growth Ti-I

experimental

frequency earlier

capable

\atisfie\

life

I I ref.

conducted is

crack

applications

cotwentional

as replacement

alloy,

of

and other

materials

Some

crack

titanium

influence

During

nuclear

damage-tolerant

high temperature

intermetallica

to

and safety-critical

in thus caw

cntrre

Effect of flowing sodium and prior exposure to sodium on LCF and creep fatigue interaction behaviour of type 316 L(N) stainless steel. Mishrcr, M.P., Bor,qsredt. H. U., V~d~cm,M.. Mnnnnn. S.L. rrnd Rodri,yur;. P. 7‘nrrrsrrr~tion.rof r/w Irrdinrr ltrstitute of Mefal.> ( 1996) 49. 497-503

ted

Influence of creep-fatigue environment interactions on fatigue growth behaviour of Ti-1100 at elevated temperature. Porida, B. K. Tmnscrctions of‘ t/w /r,dinn brstifute of Metal.\ ( 1996) 49, S3 I~550 aerospace

the

two

to the

3 ref.

strain.

Advanced

Thi\

damage

of 55 K in the reactor

in plant

data.

plug.

have

the

is acceptable.

viscoplastic

with

cracA growth

during

level

5 ref..

fatigue

analysis

increase

I.1ref.

data,

inelastic

detaded

of the adjustable The

formmg

interaction

simplification

ht.

the control

the creep

programme

data.

the confidence

square

test cases

Graphs,

The

of some

at improving

by

two

alloy.

crack

(R) levels, a simplification

literature)

stipulated

in the FCC parameter

three

load ratio

R-level

incorporating

condition

with

for

Empirical correlation for three stage fatigue crack growth at multiple load ratio (R) levels in ambient conditions. Puckinraj, C.C., Ray, S.K. crnd Mmnm. S.L. Trcrruuctions of the hIdim Imtiturr qf Mernl.\ ( 1996) 49, 55 I -55Y For correlating

to qualrfy

analyses

together

numerical

In order

accordance

bc satisfied

The

data.

of the

by applying

Creep fatigue damage assessment of PFBR control plug. Chellnpondi, P.. Romrsh. R.. Chetrd, XC. end Bhojr. S.B. 7’rcmo~~tiorrt of the h&m Irruitutr of Mcml.~( 1996) 49. SOS-S I2

viwoplnatrc

of the reactor.

methodology demonstrated

fatigue

thickness of load.

numerical

can

with

wall

all combinations

Graphs,

complete

subsequently

Maximum

and

are

The

and

pipe

The

and

have

the

tight

years

manufacturers

satisfying

testing.

safe and leak

813 K

of

shut down

different

and the detailed

of creep-fatigue

rod drive

in the CRDM.

temperature

handling

of

control

and achieve

movements

over

from

level

are used as primary

stage. This paper describes

basis,

findings

service

CRDM

the design

and its theoretical the initial

spare

bellows

at maximum

every

uses \ix

power

and gripper

operate

during

procured

Metal

continuous

cycling

at IGCAR

the reactor

translatory

bellows

undergo

temperature

(FBTR)

desired.

facilitating

to

bellows

Reactor to control

pipings. here

PHWR.

of

under

of LBB.

Creep-fatigue testing of metal bellows in sodium. Bnlachnnder. K., Rujnn, K.K., Rnmnlingnm, P., Vijo,wshrre, M.. Guptcr. SK., Chellnpnndi, P., Chrml, SC. rmd Kolr, R.D. Trmscrctionr of thr Indian Insriture of Mrtnls ( 1996) 49, 595600

PHT

Indian

be i

reactor

6 ref.

of

is described

hy enhanced

graphs.

numerrcal

37 ref.

On the bilinearity in fatigue power-law relationships in aluminium-lithium alloys. Prosnd. N.E.. M&~kondcrroh. G. curd Kutmhnrrro. 1’.1’ I’rcmnctrons of the lrrdirrrr Imtituw of’Metals ( 1996). 49, 46.5364 The of

present Al-Li

law

with

alloys.

paper

alloy\. one

\et

Various

power-law

deal\ Such

with

bilmearity

a deviation

of constant\ metallurgical

relationships

III

in the fatigue

from

an (deal

become\ factors

Al-Li

important that

alloys

lead

power-law

behaviour in life to

the

are compiled

of

rclation\hip\ wgle

poww

predictions bdinearity

of there m

and discussed.

fatigue Graph\,

26 ref.

High temperature low cycle fatigue behaviour of titanium based alloys. Mnlnkondainh. G. und Nicholm, 7 Tron.wction.s of the Indim Imtirut~~ of Mrtul.! ( lY9h) 49. 36 1464 High

temperature

alloy

in

2Nb2Cr been

alloy

studied,

2Nb2Cr

alloy

iour.

the

On

low

cycle

basket-weave

fatigue

in fully~lamellar with

and

in FL basis

behaviour

microstructural

of

without

condition\ hysteretic

01. a Ti,Al-bawd

condition

and

(FL)

and nearly-lamellartime.

obey

the well-known

energy

per

cycle

Ti-74AI-

a TiAl-based

hold

Ti-24Al-I

aluminide-

INL)

INb

ally

condttrons

unities

ha\

and Ti-46AI-

Coffin-Manson that

I I Nh

TrlhAl-

the

behave effect

of