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Weld Quality
WeldingQualification
&Certification
._._---~-----------~-------
------- --------- -- -------- ------- - ------_.~-------
.ecture 14 p1
Lecture ~3cope
• Need for welding qualification
• Codes & standards requirements- Welding procedure specifications- Welding procedure qualification- Welding operator qualification
• Company certification
___.•__. .__. -.l
----_.. - .._--- -_. -------_.
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- -_..-_.------ -_. ----_.
p2
Need IFor Weld Qualification
• Many variables influence weld quality, related tothe parts to be joined, the welding process andwelding operator skill
• The purpose of qualification is to demonstratethat welding procedures and personnel areadequately controlled and are capable ofacceptable results
• Such tests cannot foretell performance inproduc::tion. Quality of the production weldsshould be determined by inspection during andafter the actual welding.
L
Lecture 14
Codes & Standards
• Application codes & standards that specifyqualification requirements for weldinginclude:- ASME Boiler and Pressure Vessel Code
=~~~ ~~11 ~:~:~~i:e~~~~Code ill~.~lft- API 1104 Standard for Welding Pipelines and Related
Facilities- eSA W59 Standard for Welded Steel Construction
• Standards for weld qualification- AWS B2.1 Wt~lding Procedure and Performance
Qualification
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14 p4
lecture 14
Codes & Standards Requirements
• A common approach to qualify weldingprocedures is by preparation and testing ofstandard test pieces. The qualification testsneed not be repeated unless the weldingprocedure specification is changed.
• Some' pressure vessel standards require testplates to be welded at the same time as thevessel seams and subsequently tested.
• Other standards accept certain weldingprocedures as "prequalified"
pSi
e14
Welding I)rocedure Specification
• Standards normally require the contractor toprepare and qualify Welding ProcedureSpecifications (WPS)
• A WPS should define the welding variables insufficient detail to ensure that the requiredquality is met
• Standards differ with respect to the generalityor specificity of WPS- Some standards are very specific in defining the content
of a WPS e.g. ASME Section IX. Other standards aremore general
--~---~- ------------------
---~--------------
p6
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r------~----
Welding Procedure Specifications-Typical VVPS Contents
• scope• Base metal
• to simplify qualifications,standards often group basemetals by similar composition orstreng1h levels
• Welding process• Filler metal• Type of current and range• Arc voltage• Travel speed• Heat input
• Joint preparation _• Welding details• Welding positions• Preheat & interpass
temperatures• Post weld heat treatment
and finishing
--_._-------------
--~~-----------_._------------------------~
lecture 14 p7
QW-482 1992 SECI10N IX
QW~Z SUGGI5STED FORMAT FOR WELDING PROCEDURE SPECIFICATIONS (wPSI(See ClW.zOO.1, Section IX. ASME Boller end P........V~ Code'
__ pmz INt: • ... i.n- 24bifJ+___No wk Ol~ ..... (fj.to::!1 .if .... POR ....w Pi1R 01230_No Q ,...-~.fJ.....~.,r-------_. " &11~. si?fii~ :1'>. " MANOAI...
(All Mh ..................... I • ...t
-- v- l.fl.OOViE.-----=--==.::......:....--.::r----_""11I,'--- ~t;!l,---__"'""' :-:-_,...~:!Il-=-=_:--_
1'......__......-..1
0_ ONuc_......o Noe.,..-ue 0 OCher
......... "'Oducdon~.......~_Wri_D (Pdue:..........................................................lW" t' .... 101M ..... IN ....... of ...w .... ..., be-lAo ...._ol __.. _ ..__
........... ..,... MltIlllMd for fIIOIdl.......- ....._ .... 1
'BASE METAUI_' ,..... I _ .... --.!'--_,
Oft SAIe 'flwdoli type"" --.;;:,;,~ :.r....:::;l~-;:l'----'
.lpecifiwdo" tYPe '......=-" aL-"fL-...........__-'
Oft-... ..... ....J
..-..._--.P-------_~......-_,--, Gtoc"'---T~==
....__, GnIa..,_...J:I.!do=---,-,-------_~_--.-,;
l-~
-'FILLER METAU.-l c'",, , 00 I? 'A .... I
...... No.lSFAI _:>"M~~~",::;;:A.6=--!__i<=-::.::;;...;;:>;..,.~ +- _AM No. (CloooI " - 2..N<o. -----.-~---+---_'1'--------_4--------...... ,_olF _--......-:::::: \>AuI~=-...:I...L..2-=_r_--"'RJcM~-'"'lI'<\~N:.=ib=E==P..:::.....:....__-+ _
_.- A::"'~~I~==-=~.:=~f!ff~-=-=-=-=-=+f=-=-=-=-=-=-=-~=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-~=-1f=-=-=-~=-=-=-=-=-=-=-=-=-=-=-=-=-~F... T.... ,...-,-.-~ '-IEOOOOII ......................... Onhr Dept.. ASME. 22 Uw OrIN... 2300. FakfWd. NJ 07007·2300
174'
NONMANQA~AI'Pl!NDIX A QW-482
QW-4812 ee.tclo cOn..~
POSTWELD HEATTREATME~ ~071
T............ _ "'or-Il"""EEo:=...-------ro.. _ N ..t:AL- _POSITIONSI_I 5 ,._Co... a-_--='iJ"'1.J. ~
werding PwOQiellion: Up,---,Xc-_PoII.ionCllof Fillet . I- -l
(
Percent Compolit'on
G_al {Mixture' Ftow RIlle
Shtefding
Tr.Uing
Backing
ELECTRICAL CHARACTERISTICSfO~tem.nt ACo< DC $"- Rc=.U)~"ily _~ fRMtel .... Val. (R....t _
IAmpf Hd voIli range Ihoufd be hlCOrdMl for MCh "ect:rode ,il.,PQIitioft. lind thick....... nc. ,",it tnf,Jtmltion INY be ..... in -. gb.... form 1kniI. to ttult shown belo-.I
T....... EJ_ ........ T...._~W7U-'L {fhJS ~.. IIPu,. T
..- T' '0< GMAW__N==-'A:..:.. =-_-'
-.. Wi _' ",fA
1------------.---------1 GAS lOW......
_.layet'(sl
FiU., Metal
o~.
Ty.......,.
CurrentOl"~
le.g., .Remarks. Com
ments. Hot Wire
Addition. Techntque.
TOtc" Angle. Etc.!
t-'2. lo-,S;.1-u""N($.
ll-l~ _.
175
WPS Clualification
• The pu rpose of qualification is to show thatweldin!~ in accordance with the WPS willproduce sound welds with adequateproper1~ies.
• The WPS qualification requirements arespecifil:!d by the applicable standard.
• Qualification may be achieved by:1. Use of prequalified welding procedures2. Qualification tests3. Mock-up tests
L _
Lecture 14 p9
-------------
WPS Qualification
• Prequalified welding procedures- The concept of prequalification is based on the reliability
of certain provl~n procedures as defined by the code orstandard (e.g. GSA W59, AWS 01.1)
- The contractor is nevertheless required to prepare WPSdocuments and to accept responsibility for their use.
- Any deviation from the standard negates the prequalifiedstatus
~~------------------ ------------------------
~~~ -------- ---
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e 14 P 10
lecture 14
WPS Clualification
• Prequalified weldinq procedures~
• Qualification tests- Qualifk~ation tests are intended to demonstrate that theweldin!~ procedure results in sound welds with acceptablemechanical properties
- Tests need not simulate the actual conditions for a givenjob. They usually consist of conventional butt joints onplates or pipes
- Base 2lnd filler materials, welding variables and heattreatml~nts must follow production plans within specifiedranges.
- However, other variables such as joint geometry orweldin!~ position might not be considered as qualificationvariabl·es
-
P 11
-------- -------------------,1-----WPS QUcllification
• Prequalified welding procedures
• Qualification tests
• Mock-up te:sts- Mock-up tests are intended to simulate actual production
or field conditions.- Codes and standards do not require preparation of
welded mock-ups- However, mc,ck-ups can help to anticipate or avoid
problems in production. They are also useful when difficultaccess or other practical considerations may influenceresults in-situ, such as repair welding of nuclear plants.
--------- ----- -----------------
--------- -- ---
P 12
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I Tests elf Qualification Welds
• Specimens are removed from the samplewelds for examination and testing
• The type and number of tests depend on therequire!ments of the particular standard
• Commonly specified tests include:- tensile tests- guided bend tests- Charpy notch toughness tests, or other fracture
toughness tests such as drop weight tests- macro-etch tests- non-de,structive examination
L -------l
Lec:ture 14 p13
Mechanic:al Test Specimens (
TRANSVERSESPECIMEN
LONGITUDINAL WELDSPECIMEN
MINATURE ROUNDSPECIMENS DEPENDING ON T
IDENTICALDIMENSIONS
CHARPY.~~
------------ ------------- -----------
---~---------
!14 P 14
1--- -----~--.---...-------------------,
Face 8~ Root Bend Tests
WELD JOINT
FACE BEND
~~~~ROOT BEND~ SIDE BEND
Lecture 14 P 15
Guided Bend Test Jigs....,....-.:rt:r
sHClULDEflS OR -t.:t>tA
ROU.£2lS
n·IR.~·+ Itt Imlt\.. .. .. ,
2A+lfT-I/" lnJI1Jij~
r • $PEQMEN THICKNESS
T • SPECIMEN THIQ(NESS
(I) WnII11-ArouM '-I TeIt Jig
-~--~---~--~~.---~-~~-~-------- ------_._-_._~---~~---------------
(
I
e 14 P 16
ICharp:v Impact Specimen
~C--/.\..-....-_-_-_----11~I-- 1.0112 in. :::::.J II (27.1; mm) I--2.165 in. (55 mm)--I
I~~-~----_.- -----
~I I~D+r0.394 in. I I . L0.394 in.(10 mml r--i0.079 In. (10 )
12 mm) mm
~: 0.010 in.IO.2M mm)
e
Lecture 14
-------_. -------------
p17
,------Recordin!~ Test Results
• The we1dinn conditions and the test results areentered on a Procedure Qualification Record(PQR)
• If the test re~sults meet the requirements of thestandard, the PQR is certified by the contractorand the third-party inspector
• The WPS may then be issued for production
--------
314 P 18
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QW-483 1992 SEC110N IX
QW-483 SUGGESTED F(IRMAT FOR PROCEQU"E Ql.IAUFlc;ATlON RECORD WQR)(SH QW-200.2. flection IX. ASME BciIIer end P_,. V..... COde)
R-..d Ac:tue1 Conditions UMd to Weld Teat Coupon.
"""'-''''''' Ae. c- .1,-.1 L -d-j----n.....-..........----" ...... OuaIoficot_ R..... No.~B: £)12 A D...--=t..../..:-_(uV"'-"'-'5=<..!1c- _"" No. ~!i. I9J 2.. '3._ " Inl l!.119W I !.(\1AwT_CM Au......OC._.........I--MI'l~...s....uLenJL ---
(
JOINTS tQW-4021
(Pet'cenl Composition
G.slft) fMixturel Flow Rate
ed IOf e*=h ftUer metal Of ptoe:eu uwdJ
AR trQN ...., 1-1 rlcrJ
l:BtfAoi'J !: Ll ('1t,..)
ElECTRICAL C,.AR.I'CTERISTICS 1QW-4lIl1' - _" l ~ IU.I. ~CU,.... Dc~ c.e..~ I DC.<;:> ..........Pot.lty _
....... -------;;r;:-r-..-- VolU-:,....--=-,- _T E..."_s;,. lllJl'H-2.. 3. 11M0 _
_ M.... _ ..... ..l-'-'=s.=6-""---'--"4:=+"'IW1"""--"-I\{=N~\\"Q",..1 _
FILLER METALS IOW.c04t
SFA IcMcifM:.lton -:T..,.,...-::71...----~f-..,.,=='""..--1----------------------\AWS a.a'icot"", =:=....'-'"'f='k-__-I__..,~=:';:.:'O'-','-'g~_Filler Metal F.No. Lt I L
""",We'd Metal Analysis A-No._-~-.,...,-=-_1 --;<"""L_-,-----:.,...,~
SiH of Filler Melal _~"-"'_--".J.l._L_I--...3.o..;:-::...oL.'"--!CM"'":M:...L..Dt.... ------------t-------
G,oow Desl!lft of
CFor comb,,,allOf'l qu.I..~bons. the depo"led weld melal ttl
BASE METALS IOW..031 .sA I () bu. Spec.
T G<_ t!\R. B'.No. ..,_ --..-'1-----n.."..... ofTntCoupooo l).~ ItoJ
OiMwttro'TnICoupon h ~ PIPE"'...._-------------------'
'osmON IOW-<OS' 5 '-Pcnt.1Oft of G'oow ---''''-...:~=+_;_;..,.,-------Weld .....es.eon IUph.II. OowMIIII__·......U......p _0- -'- _
PREHEAT IOW-4Q6) .,,..... '" ,
P,ehe•• Temp.--~'Y'-V7~...\..-r--"""'tn T..... 't04>O' c.. M.'flj(0 , _
ThIs form CEOCOO7) _y be obIelned fTom Ih. 0n:Ier DePt.. ASME. 22 Law Drive. 8oJl23oo. F.lrfield. NJ 07007·2300
176
Ii
NONMANDATORY APPENDIX A
QW-483 (Back)
QW-483
--------
~~--------------+....;:'L~ I~ o
Splc'menNo. T-
T...T--. '- erat Ex-.
, Mils
IIr:.S'btJc; I LLL rlJiW~1f.i{.Manufacturer ...:.. _
____No _
M......-ll...... . _
OtherT....
NI'IAT_ ofT... __-=.:::..J.•1:01- _--0Ihe. • _
6t.., . I f). ~I .Dote By _
COeIaiI of reccHd of ........ illustrMive only and fNy be modified to conform to the iype and number of tescs required by the Code.'
177
~14
Changes in a qualified WPS
• If a WPS is to be revised or modified beyondthe qualified ranges of the "essential variables"it is necessary to do additional qualificationtests
• If the changE~s are within the qualified ranges ofessential variables, then a revised WPS can beissued without requalification
• A PQR may support several WPS
• Since the PQR is a certified record of aqualification test, it should not be revised.
p20
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(
Welder Performance Qualification
• WeJder or welding operator qualification testsare per1formed to determine the ability of thepersons tested to produce acceptable welds
. __._--_._-~------~----------
---_._-_._._---_._.- ---~.. __..
Lecture 14 p21
Performance Qualification Req'ts
• Most standards require each welder or weldingoperator to make one or more test welds inplate or pipe
• Variables that affect the ability of welders tomake sound welds are considered qualificationvariables. These include:- welding proc:ess- filler metal- welding position- joint detail- plate thicknElss- welding tech nique
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e14
-- ~------------------_._--------------'---
P22
,-------------------------------~
Standard Welding Positions - Plates
Te,st Position 1G Test Position 2G
Te!;t Position 3G
~---
----------------
Test Position 4G
---------- -------- -----------------------
-----------------------
Lecture 14 p23
,--------------
Welding Positions-Pipes (
~~.-t;2J.J-.l16.
Tellt Position 1G
Test Position 2G
Test Position 6G
'--------~-~._---_. -_._~
-----_._-------------~_._----------------
p24
------
Perforrnance Qualification Tests
• Test spl3cimens may be groove welds or filletwelds- groove weld qualification usually qualifies the operator to
weld bClth groove and fillet welds- fillet weld qualification limits the welder to fillet welds in
only thEI position qualified or less difficult positions
• Tests consist of either bend tests, macro-etchtests or radiography
• The weIder who prepares a test plate for aprocedure qualification is usually qualifiedwithin the variables in the WPS.
--------
lecture 14
-
p25
Performan~::e Qualification Records
• Responsibility for performance qualificationrecords lies with the employer
• After succe8sful qualification of a welder theemployer and third party inspector certify theperformancE~ qualification record.
• Most codes limit the duration of qualification tothree to six months inactivity
• For most codes qualification may be extendedindefinitely provided the welder performssatisfactory work within the stated period
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114 p26
Lecture 14
---------- -----------------------,
CompClny Certification
• Some standards extend qualification to thecompany's organisational practices- ASME Boiler and Pressure Vessel Code
• requirE~ audit by ASME of a company's quality control programbefore issuing a code symbol stamp for construction ofcompcnents
• Sectiol1 III for nuclear components requires a quality assuranceprogram
-CSA WS9/W47.1• requims employment of designated welding engineers and
welding supervisors, and preparation of welding standards andWPS uudited by Canadian Welding Bureau
-ISO 9000• generalized quality assurance program
p27