Weld Joints Of Clad Material By L D Poyyara

Clad Material What Is Clad Material / Clad Plate?Non Corrosive SS / NFS CladCS / LAS Base MaterialAny 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 Clad Bonding by Explosion / Hot Rolling / Fusion Welding.

Clad PlateBonding ProcessNon Corrosive SS / NFS CladCS / LAS Base Material

Clad Plates Base Material: CS / LAS Clad Material: SS -304, 304 L, 316, 316 L,317, 317 L, 318, 321, 347NFM / NFA Copper, Aluminium, Titanium, Monel, Inconel, Cupronickel Clad PlateNon Corrosive SS / NFS CladCS / LAS Base Material

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 thickWeld JointClad 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 Corrosion Resistant Part 2 to 5 mm thickWeld JointClad 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 Corrosion Resistant Part 2 to 5 mm thickWeld JointClad Restoration

Cladding By Weld Overlay What is weld Overlay Clad?One or more layers of corrosion resistant weld metal is deposited on CS / LAS base materialFinal Layer E 308LFirst 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 OverlaySASCDilution :- 10 to 15%Final Layer E 308LFinal Layer E 308LFirst Layer - E309First Layer E 309

Cladding By Weld Overlay Typical Section Of Weld OverlayDilution :- 15 to 20%FCAW / MIGSMAWDilution :- 20 to 25%Final LayerFinal LayerFirst LayerFirst LayerE308LE309E308LE309

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 LapLess DilutionMore Dilution

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

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

Typical Butt Weld In Clad Plate 123

Typical Fillet Weld In Clad Plates

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 materialIt is a substitute for CladCS / LAS Base MaterialVentAttachment WeldLinerLiner Attachment

Advantages- Easy to attach- Cheaper than integral clad / weld overlayDisadvantages- 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 linerCS / LAS Base MaterialVentAttachment WeldLinerLiner Attachment

Typical Liner Attachment Weld

Qualification Requirements For Weld Joints In Clad Material By L D Poyyara

Welding Qualification For Clad Material Generally Qualifications Separately Done For1) Weld Joints On Base Material2) Restoration Of Clad On Weld Joints In Base Metal 12

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 & 452Test Coupon May Be With or Without Clad

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 cladClad Stripping Clad Base MetalBase Metal Without CladdingBase Metal For Welding Qualification Weld Overlay / Clad RestorationORBase Metal With Cladding

Qualification For Weld Overlay / Clad Restoration How to qualify procedure?1Prepare WPS Format available in ASME Sec. IX

2Prepare a test coupon of P number in WPS

3Coupon may be with or without clad

4Coupon size minimum 150 mm X 150 mm

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

Qualification For Weld Overlay / Clad Restoration Test Coupon For Qualification of Weld Overlay / Clad RestorationORBase Metal Without CladdingClad Stripping Clad Base Metal With Cladding37 mm min 37 mm min

Qualification For Weld Overlay / Clad Restoration Welding Of procedure Test CouponClean the surface Weld barrier layer as per WPSWidth minimum 37 mm and length minimum 150 mmPT examine the barrier layer (optional) Acceptance as per QW 195Weld subsequent layers as per WPSPT examine the final layer Acceptance as per QW 195Each bead shall have uniform width and height

Qualification For Weld Overlay / Clad Restoration Procedure / Performance Qualification Test Coupon

Procedure Qualification For Weld Overlay / Clad Restoration 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 - 163No 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.

Procedure Qualification For Weld Overlay / Clad Restoration Chemical Analysis. QW 462.5 (a) Requires only when WPS / Spec. Calls forAll elements specified in WPS / Spec. are to be analyzed.Location of chips based on minimum thickness of clad / overlay envisaged on production welds.Acceptance LimitWithin the WPS / Spec / Clad Chemistry.

Procedure Qualification For Weld Overlay / Clad Restoration

Location Of Chemical Analysis & Minimum Thickness Qualified1st 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 PossibleX X X = Min. Overlay Thickness Qualified

Procedure Qualification For Weld Overlay / Clad Restoration 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 For Weld Overlay / Clad Restoration

Procedure Qualification Thickness range Base metal & OverlayThickness Of Test CouponBase metal thickness QualifiedWeld Overlay ThicknessMinMaxMinMaxLess Than 25 mmTest Coupon ThicknessAnyMinimum thickness where chemical analysis found within limitAnyAbove 25 mm25 mmAny

Performance Qualification For Weld Overlay / Clad Restoration How to qualify Welders Performance? QW-3811Prepare WPS & Qualify the procedure

2Prepare a test coupon of P number in WPS

3Coupon may be with or without clad

4Coupon size minimum 150 mm X 150 mm

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

Qualification For Weld Overlay / Clad Restoration Welding Of Performance Test CouponClean the surface Weld barrier layer as per WPSMinimum three beads in first layerWidth minimum 37 mm and length minimum 150 mmPT examine the barrier layer (optional) Acceptance as per QW 195Weld subsequent layers as per WPSPT examine the final layer Acceptance as per QW 195Each bead shall have uniform width and height

Procedure Qualification For Weld Overlay / Clad Restoration 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 - 163No 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 For Weld Overlay / Clad Restoration

Performance Qualification For Weld Overlay / Clad Restoration

Performance Qualification Thickness range Base metal & OverlayThickness Of Test CouponBase metal thickness QualifiedWeld Overlay ThicknessMinMaxMinMaxLess Than 25 mmTest Coupon ThicknessAnyProcedure QualifiedAnyAbove 25 mm25 mmAny

Qualification Requirements for Liner Attachmentprocedure :- 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 variablesCS / LAS Base MaterialVentAttachment WeldLinerLiner 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 examChemical analysis if required as per WPS only for procedure Each position needs separate qualification Procedure in vertical up qualifies all position Liner Attachment

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