Clad Restoration

1

Weld Joints Of Clad Material

By L D Poyyara

POYYARA CONSULTANTS 2

Clad Material What Is Clad Material / Clad Plate?

Non Corrosive SS / NFS Clad

CS / LAS Base Material

Any ferrous (CS / LAS) base plate which is integrally bonded with a thin sheet / layer of non corrosive (SS / non ferrous) material on one side.

Clad Plate


Clad Plates Bonding Process

Non Corrosive SS / NFS Clad

CS / LAS Base Material

Clad Bonding by Explosion / Hot Rolling / Fusion Welding.

Clad Plate


Clad Plates

Non Corrosive SS / NFS Clad CS / LAS Base Material

Base Material: CS / LAS Clad Material:

SS -304, 304 L, 316, 316 L,317, 317 L, 318, 321, 347

NFM / NFA – Copper, Aluminium, Titanium, Monel, Inconel, Cupronickel

Clad Plate


Clad Plates Where Clad Plates are In Use?

For Fabricating Pressure Vessels & Pipe

Lines which are subjected to high

pressure & corrosion from inside surface

Corrosion Resistant Part 3 to 5 mm thick

Corrosive

Media

Pressure Resistant PartWeld Joint

Clad Restoration


Clad Plates What is the advantage of using Clad Plates in Pressure Vessel Fabrication?

Saving in Material Cost. Allows to use low cost CS / LAS corrosive base material as pressure retaining pats for highly

corrosive fluid. An inside thin layer of non corrosive clad prevents internal corrosion


Corrosive

Media

Pressure Resistant PartWeld Joint

Clad Restoration


Clad Plates What is the disadvantage of using Clad Plates in Pressure Vessel Fabrication?

Additional Precautions in Fabrication. Cutting, WEP, Rolling, Handling, Set up, Welding, PWHT


Weld Joint

Clad Restoration Corrosive

Media

Pressure Resistant Part


Cladding By Weld Overlay

What is weld Overlay Clad?

One or more layers of corrosion resistant weld metal is deposited on CS / LAS base material

Dilution :- 5 to 8%

ESSC

Final Layer – E 308L First Layer - E309


Cladding By Weld Overlay Weld Cladding Process: ESSC – Electro Slag Strip Cladding. Applicable to large

inside area of Shell, D/E, Cone, & TS

SASC – Submerged Arc Strip Cladding Applicable to large inside area of Shell, D/E, Cone, TS

FCAW – Flux Cored Arc Welding. Applicable to Flange face, Small size TS, Pipes of smaller diameter,

MIG – Metal Inert Gas Welding. Applicable to Flange face, Small size TS, Pipes of smaller diameter,

SMAW – Shielded Metal Arc Welding. Applicable to small components and repairs of clad


Cladding By Weld Overlay Typical Section Of Weld Overlay

SASC

Dilution :- 10 to 15%

Final Layer – E 308L

Final Layer – E 308L First Layer - E309

First Layer – E 309

Dilution :- 5 to 8%

ESSC


Cladding By Weld Overlay


FCAW / MIG

Typical Section Of Weld Overlay

SMAW


Final Layer

Final Layer First Layer

First Layer

E308L

E309

E308L

E309


What Is Overlap In Weld Overlay?

The extent of covering or over lapping on previous weld bead by the adjacent bead.

40 to 50 % Over Lap

Less Dilution More Dilution

10 to 15 % Over Lap

More Thickness Less

Thickness


What Is Significant Of Overlap In Weld Overlay?

Overlap of 40 to 50% in SMAW & FCAW results in Less Dilution & more weld overlay Thickness per layer

Less dilution results weld metal chemistry more towards filler metal chemistry

40 to 50 % Over Lap 10 to 15 % Over Lap

Less Dilution More DilutionMore Thickness

Less Thickness


Overlap In ESSC & SASC

The extent of covering or over lapping on previous weld bead by the adjacent bead.

4 to 5 mm Over Lap

DilutionMinimum Overlay Thickness


Weld Joints In Clad Plates

Normally Only Base Metal Thickness Is Considered For Design Calculations

Base Metal to be welded with qualified WPS

NDT (RT, UT, MT, PT) of weld joint on base metal to be cleared prior to clad restoration

Clad to be restored by welding (SMAW, FCAW, SAW, SASC, ESSC) with qualified WPS

Base Metal Joint

Clad Restoration Clad Base Metal


Typical Butt Weld In Clad Plate

Base Metal Weld Joint

Clad Stripping Clad Base Metal

Base Metal Butt Weld

Final Weld

Base Metal Joint

Clad Base Metal

Clad Restoration – Final Layer

Base Metal Joint

Barrier Layer Clad Base Metal

Clad Restoration – Barrier Layer

1

2

3


Typical Fillet Weld In Clad Plates

3

2

1

SS 304L Clad

SS 304L Clad

SS 304L Clad

SS 304L Support

SS 304L Support

SS 304L Support

Clad Stripping

CS

CS

CS

E309

E308L

18

Liner Attachment

By L D Poyyara


What Is Liner Attachment?A thin sheet / Strip / Pipe of corrosion resistant material (SS / non ferrous) is attached on corrosive metal surface by welding along the outer edges.

Unlike clad, Liner is not an integral part of base material

It is a substitute for Clad

CS / LAS Base MaterialVent

Attachment Weld Liner

Liner Attachment


Advantages

- Easy to attach

- Cheaper than integral clad / weld overlay

Disadvantages

- Less durable compared to integral clad

- More chances for leakage through liner in service

- Frequent repair / replacement of liner in service

- Needs vent holes below each liner



Liner Attachment


Typical Liner Attachment Weld



Liner

LinerFinal Layer

1St Fillet 2nd Fillet

1 2

3

22

Qualification Requirements For Weld Joints In Clad Material

By L D Poyyara


Welding Qualification For Clad Material

Generally Qualifications Separately Done For

1) Weld Joints On Base Material

2) Restoration Of Clad On Weld Joints In Base Metal



Base Metal Butt Weld

Final Weld

Base Metal Joint

Clad Base Metal

Clad Restoration – Final Layer

1

2


Welding Qualification For Clad Material

Qualifications For Welding Of Base Material 1) Procedure As Per QW 200 & QW 451 2) Performance As Per QW 300 & 452

Test Coupon May Be With or Without Clad




OR


Qualification For Weld Overlay / Clad Restoration

Qualifications For Restoring Clad By Weld Overlay

1) Procedure & Performance As Per QW 217(b), QW 451.4 & QW 453

Test Coupon may be with or without clad


Base Metal – Without Cladding

Base Metal For Welding Qualification – Weld Overlay / Clad Restoration

OR

Base Metal – With Cladding



How to qualify procedure?1 Prepare WPS – Format available in ASME Sec. IX

2 Prepare a test coupon of P number in WPS

3 Coupon may be with or without clad

4 Coupon size minimum 150 mm X 150 mm

5 Coupon thickness minimum equal to production weld, maximum need not be more than 25 mm



Test Coupon For Qualification of Weld Overlay / Clad Restoration

OR


Clad Stripping Clad


37 mm min

37 mm min



Welding Of procedure Test Coupon

1. Clean the surface

2. Weld barrier layer as per WPS

3. Width minimum 37 mm and length minimum 150 mm

4. PT examine the barrier layer (optional) – Acceptance as per QW – 195

5. Weld subsequent layers as per WPS

6. PT examine the final layer – Acceptance as per QW – 195

7. Each bead shall have uniform width and height



Procedure / Performance Qualification Test Coupon

OR


Clad Stripping Clad


37 mm min

37 mm min Min Job Size – need not > 25 mm

Barrier Layer Final Layer

Weld Area 37 X 150 mm Min


Procedure Qualification For Weld Overlay / Clad Restoration

Physical Tests , QW – 453

1. Side Bends - Transverse to welding direction - 4 No, WQ – 161

(Location of bend specimens as per QW – 462.5)

Acceptance Standard, QW - 163

1. No open discontinuity more than 1.5 mm in any direction within the weld overlay cladding.

2. No open discontinuity more than 3 mm along the weld interface.



Chemical Analysis. QW – 462.5 (a) Requires only when WPS / Spec. Calls for All elements specified in WPS / Spec. are to be

analyzed. Location of chips based on minimum thickness

of clad / overlay envisaged on production welds.

Acceptance Limit Within the WPS / Spec / Clad Chemistry.



Location Of Chemical Analysis & Minimum Thickness Qualified

1st 2nd

3rd X

Weld inter Face Base metal

Fusion Face

1st 2nd

3rd

Weld inter Face Base metal

Fusion Face

Location of Chips for Chemical Analysis – Depth Minimum Possible

X X

X = Min. Overlay Thickness Qualified



Special Process Essential Variables. QW –251.4 Welding in each position requires separate

qualification

Welding in vertical up hill position qualifies all position ( SMAW, GMAW, GTAW).

Welding with single layer and multilayer needs separate qualification



Procedure Qualification Thickness range – Base metal & Overlay

Thickness Of Test Coupon

Base metal thickness Qualified

Weld Overlay Thickness

Min MaxMin Max

Less Than 25 mmTest

Coupon Thickness

AnyMinimum thickness where chemical analysis found within limit

Any

Above 25 mm 25 mm Any


Performance Qualification For Weld Overlay / Clad Restoration

How to qualify Welders Performance? QW-381

1 Prepare WPS & Qualify the procedure

2 Prepare a test coupon of P number in WPS

3 Coupon may be with or without clad

4 Coupon size minimum 150 mm X 150 mm

5 Coupon thickness minimum equal to production weld, maximum need not be more than 25 mm



Welding Of Performance Test Coupon

1. Clean the surface

2. Weld barrier layer as per WPS

3. Minimum three beads in first layer

4. Width minimum 37 mm and length minimum 150 mm

5. PT examine the barrier layer (optional) – Acceptance as per QW – 195

6. Weld subsequent layers as per WPS

7. PT examine the final layer – Acceptance as per QW – 195

8. Each bead shall have uniform width and height



Physical Tests , QW – 453 Side Bends - Transverse to welding direction - 4

No, WQ – 161

(Location of bend specimens as per QW – 462.5)

Acceptance Standard, QW - 163 No open discontinuity more than 1.5 mm in any

direction within the weld overlay cladding. No open discontinuity more than 3 mm along the

weld interface.


Applicable Essential variables QW – 350 & 360 No upper limit for thickness of overlay qualified

Welders qualified on Clad restoration or liner attachment are also qualified in weld overlays QW – 381 (d)

No limits in pipe diameters, if welded in longitudinal direction QW – 381 (c)




Performance Qualification Thickness range – Base metal & Overlay

Thickness Of Test Coupon

Base metal thickness Qualified

Weld Overlay Thickness

Min MaxMin Max

Less Than 25 mmTest

Coupon Thickness

Any

Procedure Qualified

Any

Above 25 mm 25 mm Any


Qualification Requirements for Liner Attachment

procedure :- WPS qualified on Groove / Fillet as per QW – 202.2 (a), (b) or (c) also qualifies for liner attachments within the essential variables, If chemical analysis is not a requirement

Performance:- Welders those who are qualified for groove / fillet welds as per QW 301 are also qualified for liner attachments within the essential variables



Liner Attachment


Alternate Qualification. QW – 218.2, QW - 383.2 (b) procedure & Performance

- Weld a liner attachment assembly as shown below as per the WPS.

- Base plate thickness min. job size max. need not be more than 25 mm

- One Cross Section from each position for macro exam

- Chemical analysis if required as per WPS only for procedure

- Each position needs separate qualification

- Procedure in vertical up qualifies all position

Liner Attachment

LinerFinal Layer

Thank You

Documents

Clad Restoration