23368117-03-06-16-WIS5-Imperfections-2006

8/13/2019 23368117-03-06-16-WIS5-Imperfections-2006

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Copyright 2006, TWI LtdWorld Centre for Materials Joining Technology

CSWIP 3.1 Welding InspectionCSWIP 3.1 Welding Inspection

TWI Training & ExaminationTWI Training & ExaminationServicesServices

Welding &Welding &MaterialsMaterials

ImperfectionsImperfections

Course Reference WIS 5Course Reference WIS 5

Course notes section reference 3, 6 & 16Course notes section reference 3, 6 & 16


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Welding ImperfectionsWelding Imperfections

All el!s "ave im#erfectionsAll el!s "ave im#erfections

Im#erfections are classe! asIm#erfections are classe! as !efects!efects"en t"e$ are of a"en t"e$ are of a

t$#e, or si%e, not alloe! $ t"e Acce#tance Stan!ar!t$#e, or si%e, not alloe! $ t"e Acce#tance Stan!ar!

A !efect is an unacce#tale im#erfectionA !efect is an unacce#tale im#erfection

A el! im#erfection ma$ e alloe! $ one Acce#tanceA el! im#erfection ma$ e alloe! $ one Acce#tance

Stan!ar! ut e classe! as a !efect $ anot"er Stan!ar!Stan!ar! ut e classe! as a !efect $ anot"er Stan!ar!

an! re'uire removal(rectificationan! re'uire removal(rectification


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Stan!ar!s for Wel!ing Im#erfectionsStan!ar!s for Wel!ing Im#erfections

)S)SE* IS+ 65-.1E* IS+ 65-.1(1998)(1998) Wel!ing an! allie! #rocesses /Wel!ing an! allie! #rocesses / Classification of geometricClassification of geometric

im#erfections in metallic materials .im#erfections in metallic materials .

0art 1 2usion el!ing 0art 1 2usion el!ing

Im#erfections are classifie! into 6 grou#s, namel$Im#erfections are classifie! into 6 grou#s, namel$

1 Cracs1 Cracs

Cavities Cavities

3 Soli! inclusions3 Soli! inclusions

4 ac of fusion an! #enetration4 ac of fusion an! #enetration5 Im#erfect s"a#e an! !imensions5 Im#erfect s"a#e an! !imensions

6 iscellaneous im#erfections6 iscellaneous im#erfections


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Stan!ar!s for Wel!ing Im#erfectionsStan!ar!s for Wel!ing Im#erfections

E* IS+ 5718E* IS+ 5718 (23)(23) Wel!ing . 2usion.el!e! 9oints in steel,Wel!ing . 2usion.el!e! 9oints in steel,nicel, titanium an! t"eir allo$s :eamnicel, titanium an! t"eir allo$s :eam

el!ing exclu!e!; . !irectl$ a##licale to visualvisualtesting oftesting of

el!s? @@@el!s? @@@(!eld s"rfaces & macro e#amination)(!eld s"rfaces & macro e#amination)


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Welding imperfectionsWelding imperfections

classificationclassification

CracsCracs


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Crac$sCrac$s

Cracs t"at ma$ occur in el!e! materials areCracs t"at ma$ occur in el!e! materials arecause! generall$ $ man$ factors an! ma$ ecause! generall$ $ man$ factors an! ma$ eclassifie! $ s"a#e an! #osition@classifie! $ s"a#e an! #osition@

*ote*oteCracs are classe! as 0lanar =efects@Cracs are classe! as 0lanar =efects@

Classifie! $ S"a#eClassifie! $ S"a#eongitu!inalongitu!inalTransverseTransverseC"evronC"evronamellar Tearamellar Tear

Classifie! $ 0ositionClassifie! $ 0ositionABABCenterlineCenterlineCraterCrater2usion %one2usion %one0arent metal0arent metal


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ongitu!inal #arent metalongitu!inal #arent metal

ongitu!inal el! metalongitu!inal el! metal

amellar tearingamellar tearing

Transverse el! metalTransverse el! metal

Crac$sCrac$s


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ain Crac T$#esain Crac T$#es

Soli!ification CracsSoli!ification Cracs

$!rogen In!uce! Cracs$!rogen In!uce! Cracs amellar Tearingamellar Tearing

Re"eat cracsRe"eat cracs

Crac$sCrac$s


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Soli!ification CracingSoli!ification Cracing

+ccurs !uring el! soli!ification #rocess+ccurs !uring el! soli!ification #rocess

Steels it" "ig" sul#"ur im#urities content :lo !uctilit$ atSteels it" "ig" sul#"ur im#urities content :lo !uctilit$ at

elevate! tem#erature;elevate! tem#erature;

Re'uires "ig" tensile stressRe'uires "ig" tensile stress

+ccur longitu!inall$ !on centre of el!+ccur longitu!inall$ !on centre of el!

Crac$sCrac$s


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Crac$sCrac$s

$!rogen In!uce! Col! Cracing$!rogen In!uce! Col! Cracing

Re'uires susce#tile "ar! grain structure, stress, loRe'uires susce#tile "ar! grain structure, stress, lo

tem#erature an! "$!rogentem#erature an! "$!rogen

$!rogen enters el! via el!ing arc mainl$ as result of$!rogen enters el! via el!ing arc mainl$ as result of

contaminate! electro!e or #re#arationcontaminate! electro!e or #re#aration

$!rogen !iffuses out into #arent metal on cooling$!rogen !iffuses out into #arent metal on cooling

Cracing !evelo#ing most liel$ in ABCracing !evelo#ing most liel$ in AB


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Crac$sCrac$s

amellar Tearingamellar Tearing

Ste# lie a##earanceSte# lie a##earance

+ccurs in #arent material or AB+ccurs in #arent material or AB

+nl$ in rolle! !irection of t"e #arent material+nl$ in rolle! !irection of t"e #arent material

Associate! it" restraine! 9oints su9ecte! to t"roug"Associate! it" restraine! 9oints su9ecte! to t"roug"

t"icness stresses on corners, tees an! filletst"icness stresses on corners, tees an! fillets

Re'uires "ig" sul#"ur or non.metallic inclusionsRe'uires "ig" sul#"ur or non.metallic inclusions


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Crac$sCrac$s

Re.eat CracingRe.eat Cracing

+ccurs mainl$ in AB of lo allo$ steels !uring #ost el!+ccurs mainl$ in AB of lo allo$ steels !uring #ost el!

"eat treatment or service at elevate! tem#eratures"eat treatment or service at elevate! tem#eratures

+ccurs in areas of "ig" stress an! existing !efects+ccurs in areas of "ig" stress an! existing !efects

0revente! $ toe grin!ing, elimination of #oor #rofile0revente! $ toe grin!ing, elimination of #oor #rofilematerial selection an! controlle! #ost el! "eat treatmentmaterial selection an! controlle! #ost el! "eat treatment


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Welding Imperfections ClassificationWelding Imperfections Classification

CavitiesCavities


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%as Caities%as Caities

Root #i#ingRoot #i#ing

Cluster #orosit$Cluster #orosit$as #oreas #ore

)lo "ole)lo "oleerringone #orosit$erringone #orosit$

as #ore D1@5mmas #ore D1@5mm

)lo "ole@1@6mm)lo "ole@1@6mm

CausesCauses

oss of gas s"iel!oss of gas s"iel!

=am# electro!es=am# electro!es

ContaminationContamination

Arc lengt" too largeArc lengt" too large

=amage! electro!e flux=amage! electro!e flux

oisture on #arent materialoisture on #arent material

Wel!ing current too loWel!ing current too lo


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'oot piping'oot piping

PorositPorosit



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Cluster #orosit$Cluster #orosit$ erringone #orosit$erringone #orosit$



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Crater #i#eCrater #i#e

Wel! craterWel! crater

Crater PipeCrater Pipe


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Crater #i#e is a s"rinage !efect an! not a gas !efect, it "asCrater #i#e is a s"rinage !efect an! not a gas !efect, it "as

t"e a##earance of a gas #ore in t"e el! cratert"e a##earance of a gas #ore in t"e el! crater

Causes:

Too fast a cooling

rate

Deoxidization

reactions and liquid

to solid volume

change

Contamination

Crater cracsCrater cracs

:Star cracs;:Star cracs;

Crater #i#eCrater #i#e

Crater PipeCrater Pipe


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Soli! InclusionsSoli! Inclusions


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Solid Incl"sionsSolid Incl"sionsSlag inclusions are !efine! as a non.metallic inclusion cause!Slag inclusions are !efine! as a non.metallic inclusion cause!

$ some el!ing #rocess$ some el!ing #rocess CausesCauses

Slag originates fromSlag originates from

el!ing fluxel!ing flux

A an! TI el!ingA an! TI el!ing

#rocess #ro!uce silica#rocess #ro!uce silicainclusionsinclusions

Slag is cause! $Slag is cause! $

ina!e'uate cleaningina!e'uate cleaning

+t"er inclusions inclu!e+t"er inclusions inclu!etungsten an! co##ertungsten an! co##er

inclusions from t"e TIinclusions from t"e TI

an! A el!ing #rocessan! A el!ing #rocess

Slag inclusionsSlag inclusions

0arallel slag lines0arallel slag lines

ac of si!eallac of si!eallfusion it"fusion it"associate! slagassociate! slag

ac of interunac of interun

fusion F slagfusion F slag


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Elongate! slag linesElongate! slag linesInter#ass slag inclusionsInter#ass slag inclusions

Solid Incl"sionsSolid Incl"sions


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ac of 2usionac of 2usion


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T$#ical Causes of ac of 2usionT$#ical Causes of ac of 2usion

el!ing current too lo

evel angle too stee#

root face too large :single.si!e! el!;

root ga# too small :single.si!e! el!;

incorrect electro!e angle

linear misalignment

el!ing s#ee! too "ig" el!ing #rocess relate! / #articularl$ !i#.transfer AW

floo!ing t"e 9oint it" too muc" el! metal :locing +ut;


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ac$ of *"sionac$ of *"sion

Incom#lete fille! groove FIncom#lete fille! groove F

ac of si!eall fusionac of si!eall fusion

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1@1@ ac of si!eall fusionac of si!eall fusion

@@ ac of inter.run fusionac of inter.run fusion

CausesCauses

0oor el!er sill0oor el!er sill

Incorrect electro!eIncorrect electro!e

mani#ulationmani#ulation

Arc loArc lo

Incorrect el!ingIncorrect el!ing

current(voltagecurrent(voltage

Incorrect travel s#ee!Incorrect travel s#ee!

Incorrect inter.run cleaningIncorrect inter.run cleaning


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ac of si!eall fusion F incom#lete fille! grooveac of si!eall fusion F incom#lete fille! groove

ac$ of *"sionac$ of *"sion


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+verla#+verla#


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+erlap+erlap

An im#erfection at t"e toe or root of a el! cause! $ metalAn im#erfection at t"e toe or root of a el! cause! $ metal

floing on to t"e surface of t"e #arent metal it"out fusing to itfloing on to t"e surface of t"e #arent metal it"out fusing to it

CausesCauses

ContaminationContamination

Slo travel s#ee!Slo travel s#ee!


tec"ni'uetec"ni'ue

Current too loCurrent too lo


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+erlap+erlap

Toe +verla#Toe +verla#

Toe +verla#Toe +verla#


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Wel! Root Im#erfectionsWel! Root Im#erfections


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Weld 'oot ImperfectionsWeld 'oot Imperfections

Incom#lete root fusionIncom#lete root fusion

Incom#lete root #enetrationIncom#lete root #enetration

CausesCauses

o Am#s(voltso Am#s(volts

arge Root facearge Root face

Small Root a#Small Root a#

2ast Travel S#ee!2ast Travel S#ee!

Incorrect Electro!eIncorrect Electro!e

AngleAngle

ContaminationContaminationArc loArc lo


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ac of root #enetrationac of root #enetration ac of root fusionac of root fusion



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ac of Root 2usionac of Root 2usionac of Root 0enetrationac of Root 0enetration


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S"rinage grooveS"rinage groove

Causes:

Insufficient weld metal

deposited in the root pass

Too fast a cooling rate during

the application of the root bead

pass

Poor welding technique

A s"allo groove cause! $ contraction in t"e el! metalA s"allo groove cause! $ contraction in t"e el! metal

along eac" si!e of t"e #enetration ea!along eac" si!e of t"e #enetration ea!



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Concave RootConcave Root

Causes:

xcessive bac! purge pressure

during TI" welding

xcessive root bead grindingbefore the application of the second

pass

welding current too high for #nd

pass overhead welding

root gap too large $ excessive

%weaving&

A s"allo groove, "ic" ma$ occur in t"e root of a utt el!A s"allo groove, "ic" ma$ occur in t"e root of a utt el!



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Concave RootConcave Root



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Excessive root #enetrationExcessive root #enetration

Causes:

'oot faces too small

'oot gap too large

xcessive amps(volts

)low travel speed

Root #enetration ea! in excess in accor!ance it" t"eRoot #enetration ea! in excess in accor!ance it" t"e

relevant s#ecification eing use!relevant s#ecification eing use!



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Excessive rootExcessive root#enetration#enetration



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Concave rootConcave root Excess root #enetrationExcess root #enetration



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Causes:

*igh +mps(volts

)mall 'oot face

,arge 'oot "ap

)low Travel )peed

)urn t"roug")urn t"roug"

A locali%e! colla#se of t"e el! #ool !ue to excessiveA locali%e! colla#se of t"e el! #ool !ue to excessive

#enetration resulting in a "ole in t"e root run#enetration resulting in a "ole in t"e root run



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)urn T"roug")urn T"roug"



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Causes:

,oss or insufficient bac!

purging gas

-ost commonl. occurs

when welding stainless

steels

Purging gases include

argon/ helium and

occasionall. nitrogen

+#idi,ed 'oot ('oot Co$ing)+#idi,ed 'oot ('oot Co$ing)


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Im#erfect S"a#e an! =imensionsIm#erfect S"a#e an! =imensions


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Weld ImperfectionsWeld Imperfections

T$#ical Causes of Im#erfect S"a#e :inclu!ing #oor toe len!;T$#ical Causes of Im#erfect S"a#e :inclu!ing #oor toe len!;

0oor el!ing tec"ni'ue is t"e usual cause t"ese0oor el!ing tec"ni'ue is t"e usual cause t"ese

im#erfections, suc" asim#erfections, suc" as

electro!e si%e for t"e ca# #asses is too largeelectro!e si%e for t"e ca# #asses is too large

el!ing s#ee! too sloel!ing s#ee! too slo el!ing current too loel!ing current too lo

arc voltage too lo :SAW an! AW;arc voltage too lo :SAW an! AW;

#oor mani#ulation of t"e electro!e#oor mani#ulation of t"e electro!e

incorrect el! ea! #ositioning ( #lacementincorrect el! ea! #ositioning ( #lacement


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S"rface and ProfileS"rface and Profile

Incom#lete fille! grooveIncom#lete fille! groove 0oor ca# #rofile0oor ca# #rofile

Excessive ca# "eig"tExcessive ca# "eig"t

0oor ca# #rofiles an!0oor ca# #rofiles an!

excessive ca# reinforcementsexcessive ca# reinforcements

ma$ lea! to stressma$ lea! to stress

concentration #oints at t"econcentration #oints at t"e

el! toes an! ill alsoel! toes an! ill also

contriute to overall #oor toecontriute to overall #oor toe

len!len!


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Incom#lete fille! grooveIncom#lete fille! grooveExcess ca# reinforcementExcess ca# reinforcement



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0oor Ca# 0rofile & 0oor Toe )len!0oor Ca# 0rofile & 0oor Toe )len!


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0oor0oor

Sto# ( StartsSto# ( Starts


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Cap and 'oot -nderc"tCap and 'oot -nderc"t

An irregular groove at t"e toe of a el! run in t"e #arent metalAn irregular groove at t"e toe of a el! run in t"e #arent metal

CausesCauses

Excessive am#s(voltsExcessive am#s(volts

Excessive travel s#ee!Excessive travel s#ee!

Incorrect electro!e angleIncorrect electro!e angle

Excessive eavingExcessive eaving


tec"ni'uetec"ni'ue

Electro!e too largeElectro!e too large

Arc lengt" too "ig"Arc lengt" too "ig"

C - dC - d t


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Cap -nderc"tCap -nderc"t

Intermittent Ca# Gn!ercutIntermittent Ca# Gn!ercut

- d


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Ca# un!ercutCa# un!ercutRoot un!ercutRoot un!ercut

-nderc"t-nderc"t

W ldi I f ti Cl ifi tiW ldi I f ti Cl ifi ti


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iscellaneous Im#erfectionsiscellaneous Im#erfections

W ldi I f iW ldi I f ti


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Welding ImperfectionsWelding Imperfectionsiscellaneous Im#erfectionsiscellaneous Im#erfections

Arc strie or stra$ arcArc strie or stra$ arc

acci!ental striing of an arc on to ase materialacci!ental striing of an arc on to ase material

loss of el!ing cale insulationloss of el!ing cale insulation

#oor connection of ?current return? cale#oor connection of ?current return? cale

S#atterS#atter

excessive current or voltageexcessive current or voltage

rin!ing mar ( mec"anical !amagerin!ing mar ( mec"anical !amage

Torn surfaceTorn surface

Mi ll I f tiMi ll I f ti


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Miscellaneo"s ImperfectionsMiscellaneo"s Imperfections

Causes: xcessive current

Damp electrodes

Contamination

Incorrect wire feed speed

when welding with the -+"

welding process

+rc blow

S#atterS#atter

Mi ll I f i


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Miscellaneo"s ImperfectionsMiscellaneo"s Imperfections

Arc strieArc strie

CausesCauses

Acci!ental striing of t"eAcci!ental striing of t"e

arc onto t"e #arentarc onto t"e #arent

materialmaterial

2ault$ electro!e "ol!er2ault$ electro!e "ol!er

0oor cale insulation0oor cale insulation

0oor return lea!0oor return lea!

clam#ingclam#ing

W ldi I f ti Cl ifi tiWelding Imperfections Classification


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ec"anical =amageec"anical =amage

M i l /M i l /


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Mecanical /amageMecanical /amage

ec"anical !amage can e !efine! as an$ surface materialec"anical !amage can e !efine! as an$ surface material

!amage cause !uring t"e manufacturing #rocess@!amage cause !uring t"e manufacturing #rocess@

rin!ingrin!ing

ammeringammering

C"isellingC"iselling

C"i##ingC"i##ing

)reaing off el!e! attac"ments)reaing off el!e! attac"ments

:torn surfaces;:torn surfaces;

Gsing nee!le guns to com#ressGsing nee!le guns to com#ress

el! ca##ing runsel! ca##ing runs

M i l /M i l /


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Mecanical /amageMecanical /amage

ec"anical =amage(rin!ing arec"anical =amage(rin!ing ar

C"i##ing arsC"i##ing ars



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Set.G# IrregularitiesSet.G# Irregularities

-ne0"al eg engts-ne0"al eg engts


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A variation of leg lengt"s on a fillet el!A variation of leg lengt"s on a fillet el!

*ote*oteGne'ual leg lengt"s on a fillet el! ma$ e s#ecifie! asGne'ual leg lengt"s on a fillet el! ma$ e s#ecifie! as

#art of t"e !esign, in "ic" case it ill not e#art of t"e !esign, in "ic" case it ill not e

consi!ere! as a !efect@consi!ere! as a !efect@

-ne0"al eg engts-ne0"al eg engts

Set -p Irreg"laritiesSet -p Irreg"larities


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Set-p Irreg"laritiesSet-p Irreg"larities

0late(#i#e inear isalignment0late(#i#e inear isalignment

:i.o;:i.o;

Angular isalignmentAngular isalignment

inear misalignmentinear misalignmentisismeasure! from t"e loestmeasure! from t"e loest

#late to t"e "ig"est #oint@#late to t"e "ig"est #oint@

Angular misalignmentAngular misalignmentisis

measure! in !egreesmeasure! in !egrees

S t - I l itiSet -p Irreg"larities


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inear isalignmentinear isalignment

Set -p Irreg"laritiesSet -p Irreg"larities


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inear isalignmentinear isalignment



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"estions"estions


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"estions"estions

Wel! Im#erfectionsWel! Im#erfections


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Material InspectionMaterial Inspection



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All materials arriving on site s"oul! e ins#ecte! forAll materials arriving on site s"oul! e ins#ecte! for

Si%e ( !imensionsSi%e ( !imensions

Con!itionCon!ition

T$#e ( s#ecificationT$#e ( s#ecification

In a!!ition ot"er elements ma$ nee! to e consi!ere!In a!!ition ot"er elements ma$ nee! to e consi!ere!

!e#en!ing on t"e materials form or s"a#e!e#en!ing on t"e materials form or s"a#e

Pipe InspectionPipe Inspection


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Condition

(Corrosion, Damage, Wall thickness Ovality, Laminations &Seam)

Specification

Weldedseam

Sie

L!"

Pipe InspectionPipe Inspection

Other checks may need to #e made s$ch as%distortion tolerance, n$m#er of plates andstorage

Plate InspectionPlate Inspection


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Sie

Condition

(Corrosion, Mechanical damage, Laps, 'ands &Laminations)

"L

Specification

Other checks may need to #e made s$ch as%distortion tolerance, n$m#er of plates andstorage

Plate InspectionPlate Inspection

'olling Imperfections'olling Imperfections


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Laminations

Segregation

Cold Laps

Direction of rolling

'olling Imperfections'olling Imperfections

Parent Material ImperfectionsParent Material Imperfections


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Parent Material ImperfectionsParent Material Imperfections

aminationamination

ec"anical !amageec"anical !amage a#a#

Segregation lineSegregation line

aminationsaminationsare cause! in t"e #arent #late $ t"e steel maingare cause! in t"e #arent #late $ t"e steel maing

#rocess, originating from ingot casting !efects@#rocess, originating from ingot casting !efects@

Segregation an!sSegregation an!soccur in t"e centre of t"e #late an! are looccur in t"e centre of t"e #late an! are lo

melting #oint im#urities suc" as sul#"ur an! #"os#"orous@melting #oint im#urities suc" as sul#"ur an! #"os#"orous@

a#sa#sare cause! !uring rolling "en overla##ing metal !oes notare cause! !uring rolling "en overla##ing metal !oes not

fuse to t"e ase material@fuse to t"e ase material@

LappingLapping


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LappingLapping

apping


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apping

LappingLapping


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LappingLapping

LaminationLamination


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LaminationLamination

aminationsaminations


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aminationsaminations

0late amination0late amination

Material imperfectionsMaterial imperfections


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An$


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"estions"estions

Wel! Re#airsWel! Re#airs


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lementslements

IronIron 2e2e

CaronCaron CC is for Strengt"is for Strengt"

anganeseanganese nn is for Toug"nessis for Toug"ness

SiliconSilicon SiSi D -@3J =eoxi!iserD -@3J =eoxi!iser

AluminiumAluminium AlAl rain refiner, D-@--7J =eoxi!iser Frain refiner, D-@--7J =eoxi!iser FToug"nessToug"ness

C"romiumC"romium CrCr Corrosion resistanceCorrosion resistance

ol$!enumol$!enum oo 1J is for Cree# resistance1J is for Cree# resistance

lementslements


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lementslements

ana!iumana!ium Strengt"Strengt"

*icel*icel *i*i o tem#erature a##licationso tem#erature a##lications

Co##erCo##er CuCu Gse! for eat"ering steels :Corten;Gse! for eat"ering steels :Corten;

Sul#"urSul#"urSS Resi!ual element :can cause "otResi!ual element :can cause "ot

s"ortness;s"ortness;

0"os#"orous0"os#"orous 00 Resi!ual elementResi!ual element

TitaniumTitanium TiTi rain refiner, Gse! a a micro allo$ingrain refiner, Gse! a a micro allo$ing

element :S&T;element :S&T;

*ioium*ioium ** rain refiner, Gse! a a micro allo$ingrain refiner, Gse! a a micro allo$ing

elementelement :S&T;:S&T;

:S&T; K Strengt" & Toug"ness:S&T; K Strengt" & Toug"ness

Stainless SteelStainless Steel


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Stainless SteelStainless Steel

23368117-03-06-16-WIS5-Imperfections-2006

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Transcript of 23368117-03-06-16-WIS5-Imperfections-2006