Analysis of results on improved welded joints

72

Fatigue

SR.30.1

10.30

(single

reheat,

low-alloy that

are

reviewed

180 har,

steels

are used

high-chrome steam

and

for

from

using

the

higher

related

MW,

more

steels

the

IP

are

rotor.

htearn

to the

design\

3000 rpm).

in the

ferritic

inlet

conditions.

and

6X0

The

advanced

used

An

for

frame

single

turbine.

relative

to

except

in contact

improvement the

Fatigue

SR.18.68.30 and the same

reheat

components

cfficlency

condition\

of

same design

of

with

-3%

the

rewltb

conventional

Asbstracts resistance

D., K/n\firu.trweh, Welding ir, r/w It

IS shown

specimens

steam

Graphs

All

o\er

the

and

-orId

These

regulatory

these

highway

can

bridges

still

Furthermore,

must

decide

u\ed

in

for

and reliable

\afcty.

Graphs.

1950s

and

in order will

the turn

under

\imilnr

1960s.

what

exist\

hridges

unknown in

for

the fatigue (0.8

heavier

both

to establish

whether

fatigue

he presented

m order

to arcs\

wth existing LI 7 ..,.I 1c1.

and

cases

theae

M.A. ( 1996)

ih critical.

A

the fatigue

the

welded

components

the fatigue weld

life

at any

A procedure

the condition simple

period

in a weld

f.racture

S/N

curves

for absebsment

of a weld

method

designed

intermediate

cracks are detected life.

arc

of the component.

before

linear

of

mechanics

impectinn

width weld

,joint\ From

elastic

fracture

Lim,~. J., Gollhordf, Far;
which

predict

the condition is carried

out to detect

fracture

of

out.

II

remaining

equlaxed fusion granular

Creep

and cyclic 95Sn-5Ag

deformation and

and an Ag-modified temperature strain

eutectic

alloy

and high (100°C

and

amplitude

up to 6.Oq’)

fatigue

lives

among

the alloy!,

alloy)

ranging

from

Graphs,

cracks.

fatigue

The

solders.

1996) 19( I I ).

(

resistance

significant effect

on

the

97.SPh-I very

Ag

significant

primary

ha?, to take of alloy

built

upon

a two-cell

This

model

provides

the

tow.

Graph\,

and

Sn-Ph

eutectic show

wa\ which

in each strain

creep

covers

a good estimate stress

a comparison

cycle);

fatigue

life

with

Recent

studies

allows

an increase

The

aim

have

of this study

base containing analysi\

the crack Both

has a

rule may

3. Four

peening,

longitudinal in air

classes

of yield

strength

>600.

All

curves

results

were

strength

with

S-N

or even life.

a stress

obtained phase

ratio

creep.

into

results is very

were

with

above

hammer

those

in addition

Graphs,

The

I IS ref.

duration

of

peening.

The

phase

a data

of parameters

influencmg

are compared

(butt,

Joint

and many

wcondar)

crack\

IX ref.

give

T joint\,

0.1

were

increases

quite

1400,

Effect

of surface

The effect of

model

growth

result\ on

determmation in

studie\

fatigue

lift,

are

i\ used in determinatmn predlctiona

Graph\.

r&dual

obtained

the

results

approach.

welding

IS considered.

and analytlcal

and experimental

treatment

rewltr show

of the fatigue

the

of

the

gl\en_

of the analytical

ohtamed

A

of

A

I\ ohtalned. fatigue

that the Miner

llfr

for the type\

30 ref.

on the fatigue failure behaviour

Z. S~~icrrw

of surface

( 1996)

I,cmw

preparation

adhesive-bonded

studied.

cloth

ratio

structural

Suhstmte\

wth

15(h).

showed

adhewe

slowly that

surface

of adhesive

between

of structural

469--172

mechanical menreg

Increased

factors

of the joints

and tat&we

aluminum

pretreatment

(AF-163.2K. doe\

not

suhatrate

of

thickne\\

(K,IK,,).

Mechanical

rcmarkahly.

Graphs.

howled

heat

fatigue

affect

tiietimc

xhcet\

acre

3M).

Rewlts

pretreatment

bonds.

wength

7075.T6

to room’&p&~ture.

of stress intensity lifetime

on the interfacial jomt\

or without

structural

to cool

the

cured. test\

static

resulted

pretreatment

wa\ using and

of

the

loading

in increased increased

photomicrographs.

the

10 ref.

Improvement of corrosion fatigue limit of steam turbine blades. [Amelioration de la limite d’endurance en fatigue-corrosion d’ailettes de turbines

<25

mm Three

The experimental of alloyed

400-600,

for

The

blade\

he\t

conditions

steel5 are defined

improving made on

121

in low

aggressive

During

is slowed total

the down

fatigue

do

sacrificial

not

interesting I4

ref.

improve

used to determine from

the endurance

of the

the

crack

experimental

\tudled.

H. and Ah&/, of Matcrink

peening

with

the

influence

the

analytical

fracture

adhesive joints. Aglrrrl, Jmwnal

deposit.

phase.

an

mechanw

of

for

using

plate test \pecimew

influence

fatigue

Furthermore, have

obtained

welded

using a fracture the

model

unconscrvntivc

loading

in the fatigue

defects

closure

between

closure

due to the occurence

propagation

crack-like

that

and rewlts

for St. 52-3

01 special connection,

dressing,

selected.

increase

was

crack

the

is \tudicd. and in th!\

cruciform

assemblies.

larger

result\

life,

on

loadmg

accumulation

predictions

closure

based on fracture mechanics

to those

TIG

thicknesses

considered:

techniques

rate of

>lOOR).

create

a statistical

as-welded

to the crack this

types

were

and rctined

growth

on welds

(even

(grinding,

0 and

of the existing of

.J.J.

make

which

account.

R between

raw

effect improve

&a

Jmo.wh.

data,

rewlts.

tcchniqueb

for the base metal

phase, the extension stopped.

curves

and four joint taken

literature

the effect

S-N

due to the use of improvement

of an initiation initiation

new

will

a

Cyclic

rate

techniques

strength

and fatigue

improvement

were

loaded

and validate

to quantify

shot peening) joints)

fatigue

fatigue

the analytcal

of stochastic

fatigue

the use 01. improvement

characteristtcs order

H. nnd

lift

the

agreement

live\.

relation

minimu&

strain

good

hehaviour

Chnbrolm.

of admissible

and propose

in Eurocode

hammer and

the ioint

strength

that level

was to collect

of the data’in

the fatigue given

shown m the

had po\iti\c

crack

are

fracture

than that of base Imetal. Traw

to stochastic

experimental

included.

when

conatitut-

experimental

the applied

very

welded joints.

Souissi. R., Nus~boumrr, A.. World (1996) 37(S), 242-226

elastic

of fast cooling

mcchaniam

damage

of

the

i\

strain

have

and secondary (the

of

parameter\

joints H.P., in /he

material

and

Strength

propertie\

on lmenr

photomicrographs,

subjected

fatigue

crack

life

vxim

Lieurode, Weldiq

fatigue

cmch

\pecd

and

generally

a constitutive

primary

and

various

has a negligible

into consideration.

by using

with

fatigue

S ref.

of results on improved

of weld

the fatigue

lower

fracture

while

tiller

Also.

are

on the fatlytic

speed or gap width

because

tc\t results obtained

calculation

the

(\tram

highest

Temperature

alloys

the

allowed

Analysis

zone

of fatigue

between

that

eutcctic

thus, any reahstic

it agrees

In

with hhown

62.SSn-36.IPbbl.4Ag

phase

and/or

test.

wre

7onc

done. Graphs.

Fatigue

arc compared

dexription

Sn-Ph

hut

these

both

Graph\

rate arc conudered.

teht haxd

welding

growth

i\ the typical

in steel structure\

cyclic

has the

of the peak- stress&

is small

Photomicrographs,

alloy

simulated

thicknesea

and compared

H apecimcn

influence

growth

the added

crack

is the problem

tebts (with It i\

cycle

(AE > 2.0%).

(up to 20%);

such a primary

cyclic

of low

that

The

hy a tensile

in fusion

Fatigue

\treaae\

modified

99Sn~I.OCu.

studies

crack

Increasing

to fatigue

weldmg

steel.

propagation

the result\,

interest

Room

conducted,

cycles.

.SAg-I.OSn,

region

model,

were

(the

in term

strain

9SSwSAg

maximum

the applied

soldera

97.SPh-I

creep regime

fatigue

to >I00000

9SSn-5Ag

Creep

ive relation

when

large

modified

deformation

and

alloy

on alloys

SAg-I.OSn.

four

resistance

lead

in the

effect

the cycles

crach

properties.

fracture

studied.

were

temperature

solder

97.SPhb.SAg~l.OSn.

62.5Sn~36.lPhbl.4Ag,

for

the

and

specimen.

metal

analyvzd

spot

in a cold rolled steel.

An analytical model for fatigue life prediction and crack closure.

W.L.

high temperature

alloy

62.SSn~36.lPhbl.4Ag

fatigue

high

lead-free lead

wing

of load\

This

12 ref

S.A. md Morris, and S~ruc~tuw

of two a high

150°C)

a few

studied.

has the lowest

controlled).

behavior

99Sn~l.OCu.

cvuluated

fatlgur

in the fuwm

labcr

rolled

on fatigue

and heat affected

mechanic\. alloy?,

i\

of

cold

microstructure

zone

appear

envelope?, by combining

of four high temperature

N.. Lee, P.S., Schroeder. of En,~irrwrin,q Mnterio/.\

determmed

II

the D.C.

sheet

are

;I

\pcclmen’.

external

With

different

wength

dexrihc\

to \ihr;ttion\

bearable

the rewlts

\tiffne\\

that can he used to verify

mechanics.

A study of fatigue and creep behavior

curves

the effect

of hutt joint

mechanics.

is carried

using linear

~aIue\

in SPCC-CQI

on the fatigue

is used to tind their here

on two

thickness.

of laser weldments

dexrihc?,

337-364

inspection

determined one

(DC)

stability

of

proces\

paper

hy

SIN

The

form

low

fatigue

paper

the ‘Double-Cup

This

Investigated

to ascertain

its life

is developed

has been developed

with

using

In order

This

I446

the resi\tancc Presently only

part,.

tcu

determining the chwactw

therefore.

stresses on the spot weld.

characteristic

of welds in bridges.

4(4).

i\ For

the

part\:

wch

the work. in

tcn\ion

and

of the too

Hwnn,q. J.-R. Doomy. J.-I.. md Chm C.-C. Matfwiul.\ 7‘rcr,,.rri~,r~~,,l. .JIM ( 1996) 37(X ), I44.1-

of the G‘/~o.s/r. A.. Oehlrrc. D.J. nrzd Wahnb. Stncuwrl Dt#rcrrirr~~ wrd Mrchmrio

of

strucutral

Fatigue crack growth

pap

for fatigue assessment

results

of

by using

presented

I.0 mm).

propagation

envelopes

design

i\

(;rc&,.

are often

IO ref.

Linear fracture

used

cro\\

for determimng

hecaue

to construction

wistance

and

load\

and

parameter\

arc unsuitable

vihmtional

in the

0,

at the time.

has become

Therefore,

the

Owner\

condition\

problem

These

bridges

of

old or more.

relatively

significantly.

procedure

around

and A

was

and railway

increased

must he re-assehxd

simple

built

100 year\

future.

Fatigue

on highway

have

were whether

the

in the

suitable

traffic

wIume\

bridges

he

constructed

hut detailing

traffic

hridgcs

and are now

load\

peel

joining

ah compared

initial

nominal

shear,

defining

this prohlcm

clement\

calculated

railway

hc

on the

welded

are riveted

authorities

bridge\

welded,

many

bridge\

cannot

report\

Hirr, M.A.
century.

qua+static

means of avoidmg

bestehender

for

loads. Ho/m

2 17-221

overlapped

used

m the case of

bpecimens

results

[Ermudungssicberbeit

\tandardued are

under

values

of thcx

Fatigue safety of existing steel bridges. Brucken aus Stahl.].

that which

resistance i\tic

of spot welds under multiaxial

11 md Rohdc,. A. World ( 1996) 37(S).

coating), Cr steel

environments the

solution

limit

in the

Cr steel are estimated:

12%

shot

peening,

makes

(water

corrosive

acquired

protective the

use

of

coating of

25%

to increase

and water + NaCI). behavior.

environmenta.

25%

hchuvlour

at CERM.

fatiguexorrosion

it possihlc

fatigue-corrosion for

the fatiguexorrosion

the experience

Solutions

\teanl

electrolytic

Cr

jteet.

the endurance The coating\

Cr

Graphs,

turhme

(Ni

steel

may

Shot limit studied bc

photomicrographs.

an