Welding Inspection.ppt

7/25/2019 Welding Inspection.ppt

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Gas CavitiesGas Cavities 3.63.6

Root pipingRoot piping

Cluster porosityCluster porosityGas poreGas pore

Blow holeBlow holeHerringbone porosityHerringbone porosity

Gas pore 1.6mm

Causes:Causes:

Loss o gas shiel!Loss o gas shiel!

"amp ele#tro!es"amp ele#tro!es

ContaminationContamination

$r# length too large$r# length too large"amage! ele#tro!e lu%"amage! ele#tro!e lu%

&oisture on parent material&oisture on parent material

'el!ing #urrent too low'el!ing #urrent too low


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Root pipingRoot piping

PorosityPorosity

Gas CavitiesGas Cavities 3.73.7


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Crater pipeCrater pipe

'el! #rater'el! #rater

Crater (ipeCrater (ipe ).*).*


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Crater pipe is a shrin+age !ee#t an! not a gas !ee#t, it hasCrater pipe is a shrin+age !ee#t an! not a gas !ee#t, it has

the appearan#e o a gas pore in the wel! #raterthe appearan#e o a gas pore in the wel! #rater

Causes:Causes:

Too fast a coolingToo fast a coolingraterate

Deoi!i"ationDeoi!i"ation

reactions an!reactions an!

li#ui! to soli!li#ui! to soli!volu$e c%angevolu$e c%ange

Conta$inationConta$ination

Crater #ra#+sCrater #ra#+s

-tar #ra#+s/-tar #ra#+s/

Crater pipeCrater pipe

Crater (ipeCrater (ipe ).*).*


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'oli! (nclusions'oli! (nclusions3.103.10'lag inclusions are !efine! as a non)$etallic inclusion'lag inclusions are !efine! as a non)$etallic inclusion

cause! *+ so$e ,el!ing -rocesscause! *+ so$e ,el!ing -rocess Causes:Causes:

lag originates romlag originates rom

wel!ing lu%wel!ing lu%

&$G an! 0G wel!ing&$G an! 0G wel!ingpro#ess pro!u#e sili#apro#ess pro!u#e sili#a

in#lusionsin#lusions

lag is #ause! bylag is #ause! by

ina!e2uate #leaningina!e2uate #leaning

3ther in#lusions in#lu!e3ther in#lusions in#lu!e

tungsten an! #oppertungsten an! #opper

in#lusions rom the 0Gin#lusions rom the 0G

an! &$G wel!ing pro#essan! &$G wel!ing pro#ess

lag in#lusionslag in#lusions

(arallel slag lines(arallel slag lines

La#+ o si!ewallLa#+ o si!ewallusion withusion with

asso#iate! slagasso#iate! slag

La#+ o interunLa#+ o interun

usion 4 slagusion 4 slag


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el!ing ($-erfectionsel!ing ($-erfections 3.133.13

0ypi#al Causes o La#+ o usion:0ypi#al Causes o La#+ o usion:

wel!ing #urrent too low

beel angle too steep

root a#e too large -single7si!e! wel!/

root gap too small -single7si!e! wel!/

in#orre#t ele#tro!e angle

linear misalignment

wel!ing spee! too high

wel!ing pro#ess relate! 8 parti#ularly !ip7transer G&$'

loo!ing the 9oint with too mu#h wel! metal -blo#+ing 3ut/


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ac of usionac of usion3.133.13

n#omplete ille! grooe 4n#omplete ille! grooe 4

La#+ o si!ewall usionLa#+ o si!ewall usion

11

1.1. La#+ o si!ewall usionLa#+ o si!ewall usion

.. La#+ o inter7run usionLa#+ o inter7run usion

Causes:Causes:

(oor wel!er s+ill(oor wel!er s+ill

n#orre#t ele#tro!en#orre#t ele#tro!e

manipulationmanipulation

$r# blow$r# blow

n#orre#t wel!ingn#orre#t wel!ing

#urrent;oltage#urrent;oltage

n#orre#t trael spee!n#orre#t trael spee!

n#orre#t inter7run #leaningn#orre#t inter7run #leaning


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La#+ o si!ewall usion 4 in#omplete ille! grooeLa#+ o si!ewall usion 4 in#omplete ille! grooe

La#+ o usionLa#+ o usion ).1)).1)


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'el! Root mpere#tions'el! Root mpere#tions ).15).15

La#+ o Root usionLa#+ o Root usionLa#+ o Root (enetrationLa#+ o Root (enetration


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'urface an! rofile'urface an! rofile 3.193.19

n#omplete ille! grooen#omplete ille! grooe (oor #ap proile(oor #ap proile

%#essie #ap height%#essie #ap height

(oor #ap proiles an!(oor #ap proiles an!

e%#essie #ap reinor#ementse%#essie #ap reinor#ements

may lea! to stressmay lea! to stress

#on#entration points at the#on#entration points at thewel! toes an! will alsowel! toes an! will also

#ontribute to oerall poor toe#ontribute to oerall poor toe

blen!blen!


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La#+ o si!ewall usion 4 in#omplete ille! grooeLa#+ o si!ewall usion 4 in#omplete ille! grooe

n#omplete Grooen#omplete Grooe).)).)


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Con#ae RootCon#ae Root

Causes:Causes:

cessive *ac -urgecessive *ac -urge

-ressure !uring T(G ,el!ing-ressure !uring T(G ,el!ing

cessive root *ea! grin!ingcessive root *ea! grin!ing

*efore t%e a--lication of t%e*efore t%e a--lication of t%e

secon! -asssecon! -ass

,el!ing current too %ig% for,el!ing current too %ig% for2n! -ass2n! -assover%ea! ,el!ingover%ea! ,el!ing

root ga- too large ) ecessiveroot ga- too large ) ecessive

5,eaving5,eaving

$ shallow grooe, whi#h may o##ur in the root o a butt wel!$ shallow grooe, whi#h may o##ur in the root o a butt wel!

'el! Root mpere#tions'el! Root mpere#tions).=).=


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&is#ellaneous mpere#tions&is#ellaneous mpere#tions ).6).6

$r# stri+e$r# stri+e

Causes:Causes:

$##i!ental stri+ing o the$##i!ental stri+ing o the

ar# onto the parentar# onto the parent

materialmaterial

aulty ele#tro!e hol!eraulty ele#tro!e hol!er

(oor #able insulation(oor #able insulation

(oor return lea!(oor return lea!

#lamping#lamping


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iscellaneous ($-erfectionsiscellaneous ($-erfections 3.273.27

Causes:Causes:

cessive currentcessive current

Da$- electro!esDa$- electro!es

Conta$inationConta$ination

(ncorrect ,ire fee!(ncorrect ,ire fee!

s-ee! ,%en ,el!ings-ee! ,%en ,el!ing

,it% t%e 8G ,el!ing,it% t%e 8G ,el!ing-rocess-rocess

8rc *lo,8rc *lo,patterpatter


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8 ,el!ing -ara$eters8 ,el!ing -ara$eters

Travel s-ee!Travel s-ee!

0rael0rael

spee!spee!0oo high0oo high0oo low0oo low

wi!e wel! bea! #ontourwi!e wel! bea! #ontour

la#+ o penetrationla#+ o penetration

burn7throughburn7through

la#+ o root usionla#+ o root usion

in#omplete rootin#omplete root

penetrationpenetration

un!er#utun!er#ut

poor bea! proile,poor bea! proile,

!ii#ult slag remoal!ii#ult slag remoal


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T+-e of current:T+-e of current:

voltage !ro- in ,el!ing ca*les is lo,er ,it% 8Cvoltage !ro- in ,el!ing ca*les is lo,er ,it% 8C

in!uctive looses can a--ear ,it% 8C if ca*les are coile!in!uctive looses can a--ear ,it% 8C if ca*les are coile!

c%ea-er -o,er source for 8Cc%ea-er -o,er source for 8C

no -ro*le$s ,it% arc *lo, ,it% 8Cno -ro*le$s ,it% arc *lo, ,it% 8C

DC -rovi!es a $ore sta*le an! eas+ to strie arcDC -rovi!es a $ore sta*le an! eas+ to strie arc

es-eciall+ ,it% lo, current *etter -ositional ,el! t%ines-eciall+ ,it% lo, current *etter -ositional ,el! t%in

s%eet a--licationss%eet a--lications

,el!ing ,it% a s%ort arc lengt% lo, arc voltage; is easier,el!ing ,it% a s%ort arc lengt% lo, arc voltage; is easier

,it% DC *etter $ec%anical -ro-erties,it% DC *etter $ec%anical -ro-erties

DC -rovi!es a s$oot%er $etal transfer less s-atterDC -rovi!es a s$oot%er $etal transfer less s-atter


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el!ing currentel!ing current

< a--ro. 3& 8/$$ of !ia$etera--ro. 3& 8/$$ of !ia$eter

< governe! *+ t%icness t+-e of =oint an! ,el!inggoverne! *+ t%icness t+-e of =oint an! ,el!ing

-osition-osition

'el!ing'el!ing#urrent#urrent

0oo high0oo high0oo low0oo low

poor startingpoor starting

slag in#lusionsslag in#lusions

wel! bea! #ontour toowel! bea! #ontour toohighhigh

la#+ ola#+ o

usion;penetrationusion;penetration

spatterspatter

e%#esse%#ess

penetrationpenetrationun!er#utun!er#ut



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8rc lengt% > arc voltage8rc lengt% > arc voltage

$r#$r#

oltageoltage0oo high0oo high0oo low0oo low

ar# #an be e%tinguishe!ar# #an be e%tinguishe!

stubbing?stubbing?

spatterspatter

porosityporositye%#esse%#ess

penetrationpenetration

un!er#utun!er#ut


olarit+: DC generall+ gives !ee-er -enetrationolarit+: DC generall+ gives !ee-er -enetration


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8 ) Trou*les%ooting8 ) Trou*les%ooting

&&$ 2uality -let to right/&&$ 2uality -let to right/

#urrent, ar# length an! trael spee! normal@#urrent, ar# length an! trael spee! normal@#urrent too low@#urrent too low@

#urrent too high@#urrent too high@

ar# length too short@ar# length too short@

ar# length too long@ar# length too long@

trael spee! too slow@trael spee! too slow@trael spee! too hightrael spee! too high

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Welding Inspection.ppt