ASME Sec IX

General

guide lines for procedure and

performance qualification Referenced

by

all

ASME

code

of

construction 

Covers welding as well as Brazing

operations

WPS: 





It is a written procedure prepared to provide welding parameters for making welds as per code requirement. Can be used on production only after successful qualification of supporting PQR(s). A WPS can be supported by one or multiple PQR(s).

PQR: 





Record of the actual welding data used to weld a test coupon. Also contains test results (Mechanical, Chemical & Non Destructive Test) of the test coupon.

One PQR can support one or multiple WPS(es).

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Code of construction Detailed drawing of weldment Material Thickness Configuration Process





 



Contract/Customer/ Code/TPI Preheat/Postheat/ PWHT requirements Skilled welder Good welding m/c with accessories Application

Variables are defined for each process in QW-250 through QW-280 •

•Each variable shall be addressed with facts, e.g. yes, no, none or any other meaningful definition

• A PQR is a record of welding data used to weld a test coupon • It is a record of actual variables recorded during the welding of the test coupons • PQR shall document all essential and, when required, all supplementary essential variables for each welding process • Nonessential variables may be recorded (optional) • All variables are actual values used during welding of the test coupon • Changes to a PQR are not permitted as it is a record of what happened during a particular welding test, except for editorial corrections and addenda •

All changes except editorial and those invoked by an

        

Preheat  PWHT Joint design Backing material  P Number Welding Process Filler metal  Electrode Method of back gauging

Essential Nonessential Supplement al essential

Essential variable: A change in welding condition which will affect the mechanical properties other than toughness of weldment Any change in this variable calls for re-qualification of PQR

Supplementary – essential variable:

•A Change in welding condition which will affect impact toughness of weldment •Change in this variable calls for re-qualification of PQR in case there is requirement of impact toughness for the vessel

Non - essential variable:

•No change in mechanical properties is expected

A WPS shall record all essential, supplementary essential & non essential variables

QW 402: Joints •Non essential variables Groove design, Backing, Root gap, Retainers

-

QW 403: Essential variables   

P No, Thickness of base material qualified, Thickness of each pass beyond 13 mm for multipass welding

• Supplementary  

-

essential variables

Group no for base material Minimum thickness of base material qualified

-

Base Metal P Numbers P1 - P11 P21 - P25 P31 - P35 P41 - P47 P51 - P53 P61 - P62

Steel Al alloys Cu alloys Ni alloys Ti alloys Zr alloys

Base Metal P Numbers Examples of P nos P1 P3 P4 P5A P6 P7 P8 P9A P10A P11

C Steel 1/2 Mo steels 1 Cr 1/2 Mo steels 2 1/4 Cr 1 Mo steels 13 Cr steel 17 Cr steel ASS 2 1/2 Ni steels Mn - 1/2 Ni - V steels 9 Ni steels

Base Metal for WPS   Test Coupon qualified Px - Px Px - Py P3 - P3 P4 - P4 P5A - P5A P3, P4 - P3, P4 - P1 P5A - P4, P5A - P3} P5A - P1

Base Metal Px Px to Py P3 - P3, P3 - P1 P4 - P4, P4 - P3, P4 - P1 P5A - P5A, P4 - P4, P4 P4 - P1 P4 - P3, P4 - P1 P5A - P4, P5A - P3 } P5A - P1

Tensile Specimens CTOD Specimens

Impact Specimens

Non Destructive Exam Visual- DPI- MPI- RT- UT

Bend Tests

Fillet Weld Fracture

QW 404: Essential variables -

•F no, •A no, •Thickness of deposited weld metal •Flux / wire class, •Alloy addition through flux (SAW), •Re-crushed slag (SAW)

Supplementary essential variables •Electrode Diameter > 6 mm for SMAW

Non essential Variables –

•Change of Electrode Diameter for SAW

F - NUMBERS

F-Number grouping of electrodes & welding rods is based essentially on their usability characteristics to reduce the number of tests required to qualify procedures and welders.

A - NUMBERS

Used to describe the weld deposit chemistry and is applicable only to the ferrous metals for the qualification of a welding procedure.

F Number

Description

1

Heavy Rutile Coated Iron Powder Electrode

2

Most Rutile Coated Iron Powder Electrode

3

Cellulosic Electrodes

4

Basic Coated Electrodes

5

High Alloy austenitic stainless steel & Duplex Stainless steel Electrodes

6

Any Steel or coated Wire (with flux or Metal)

2X

Aluminum & Its Alloys Electrodes

3X

Copper & Its Alloys Electrodes

4X

Nickel & Its Alloys Electrodes

5X

Titanium & Its Alloys Electrodes

F Number

ASME Specification

AWS Classification

4

SFA 5.1

E7018, E7018-1

6

SFA 5.18, 5.28, 5.29, 5.30

All classification

43

SFA 5.11

ENiCrFe-2, ENiCrFe-3

43

SFA 5.14

ERNiCr-3

71

SFA 5.13

ECoCr-A, ECoCr-B ECoCr-C, ECoCr-E

Weld Metal Analysis, % [Single values shown are maximum ]

ANo .

Types of Weld Deposit

1

C

Cr

Mo

Ni

Mn

Si

Mild Steel

0.20

…

…

…

1.60

1.00

2

Carbon-Molybdenum

0.15

0.50

0.40-0.65

…

1.60

1.00

3

Chrome (0.4% to 2%)Molybdenum

0.15

0.40-2.00

0.40-0.65

…

1.60

1.00

4

Chrome (2% to 6%)Molybdenum

0.15

2.00-6.00

0.40-1.50

…

1.60

2.00

5

Chrome (6% to 10.5%)-Molybdenum

0.15

6.0010.50

0.40-1.50

…

1.20

2.00

6

Chrome-Martensitic

0.15

11.0015.00

0.70

…

2.00

1.00

7

Chrome-Ferritic

0.15

11.0030.00

1.00

…

1.00

3.00

8

Chromium-Nickel

0.15

14.5030.00

4.00

7.5015.00

2.50

1.00

9

Chromium-Nickel

0.30

19.0030.00

6.00

15.0037.00

2.50

1.00

10

Nickel to 4%

0.15

…

0.55

0.80-4.00

1.70

1.00

11

ManganeseMolybdenum

0.17

…

0.25-0.75

0.85

1.25-2.25

1.00

12

Nickel-ChromeMolybdenum

0.15

1.50

0.25-0.80

1.25-2.80

0.75-2.25

1.00

QW 405: Supplementary essential variables -

•Change from any position to vertical uphill progression for SMAW.

Non essential variables – •Change in position.

QW 406: Essential variables -

•Decrease of more than 55ºC in the preheat temperature qualified.

Supplementary essential variables -

•Increase of more than 55ºC in the interpass temperature qualified.

Non essential variables –

•Change of preheat maintenance Treatment (DHT) etc.

i.e. Dehydrogenation

QW 407: Essential variables -

•Any change in the following conditions: No PWHT, PWHT below lower transformation temperature, PWHT above upper transformation temperature, PWHT between upper & lower transformation temperature.

Supplementary essential variables –

•Increase in job PWHT soaking time beyond 20% of the soaking time qualified in PQR.

QW 408

:

•Essential variables

Single shielding gas to mixture of gasses, Different types of mixed gasses, Percentage composition of gasses for GMAW, FCAW, GTAW process

•Non essential variables Flow rate, Backing gas flow rate Backing gas composition

–

QW 409: •Supplementary essential variables Increase in heat input , Change in current type ( AC / DC), Change in Polarity (DCEN / DCEP)

•Non essential variables – Change in current range, Change in range of voltage (except SMAW & GTAW)

QW 410: Supplementary essential variables-

•Change in multiple to single pass per side . •Change of Single to multi electrode for SAW

Non essential variables –

•Change of Stringer bead to Weave bead technique or vice versa, •Method of cleaning, •Method of back gouging,

Purpose

•To validate the capability of an welder to deposit sound weld metal following a qualified welding Procedure •Establish the range of qualification to minimize the number of qualification •Guide line for renewal of qualification

Welder

•Person performing welding by manipulating arc by hand

Welding Operator

•Person performing welding by controlling the manipulation

A change in welding condition which will affect the ability of welder to deposit sound weld metal Any change in this variable calls for requalification Essential Variables Change in welding Process  Change from direct to remote visual control  Deletion of Auto joint tracking  Addition of welding position not qualified  Deletion of consumable inserts  Deletion of backing Single pass per side to multi pass per side

OD of Test coupon,mm

Minimum OD Qualified, mm

Less than 25 mm

Size welded

25 to 73,mm

25 mm

Over 73 mm

73 mm

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Welding Performance Qualification Test coupon More than 2 welders different procedure can do a single test coupon. Failure then both are failed.   Retest - 2 consecutive test coupons to pass

    1. 2. 3. 4. 5. 6. 7.

Renewal if no welding for 6 months. Single test coupon plate/pipe, any thickness, material, position. If passed then complete previous qualification is restored.   Welding Performance Qualification Variables for SMAW Removal of backing Change in Pipe diameter Change in P number Change in F Number Change in thickness of weld deposit Change in welding position

   1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

Variables for GTAW Removal of backing Change in Pipe diameter Addition / deletion of filler metal Addition / deletion of insert Change in P number Change in F Number Change in solid filler to flux cored filler metal Change in thickness of weld deposit Change in welding position Removal of inert gas backing Change in current or polarity

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Radiography

No crack or LOP or LOF Any elongated slag 1/3 t for t = 3/8 - 2 1/4”

>1/8” for t 2 1/4”

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Any group of slag in a line with aggregate length t in 12 t unless separated by 6L

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Max permissible dimension for rounded indication smaller of 20% of t or 1/8” For thickness1/8”, charts for max acceptable types of rounded indication

PLATE QUALIFICATION   Visual examination Radiography 2 no of Tensile test 2 no each of Bend test - face and root bend ( 3t for both C steel and alloy steel 180 deg bend) 1 no Micro examination 1 no Macro examination PIPE QUALIFICATION Visual examination Macro examination 2 no each of Bend test - face and root bend ( 3t for C steel and 4t for alloy steel 90 deg bend)    

PLATE QUALIFICATION Radiography 1 no each of Bend test - face and root bend   PIPE QUALIFICATION 1 no each of bend test - face and root bend Macro examination