1Weld 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 POYYARA CONSULTANTS 3 Clad Plates Bonding Process Non Corrosive SS / NFS Clad CS / LAS Base Material Clad Bonding by Explosion / Hot Rolling / Fusion Welding. Clad Plate POYYARA CONSULTANTS 4 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 POYYARA CONSULTANTS 5 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 Part Weld Joint Clad Restoration POYYARA CONSULTANTS 6 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 thick Corrosive Media Pressure Resistant Part Weld Joint Clad Restoration POYYARA CONSULTANTS 7 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 thick Weld Joint Clad Restoration Corrosive Media Pressure Resistant Part POYYARA CONSULTANTS 8 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 POYYARA CONSULTANTS 9 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 POYYARA CONSULTANTS 10 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 POYYARA CONSULTANTS 11 Cladding By Weld Overlay Dilution :- 15 to 20% FCAW / MIG Typical Section Of Weld Overlay SMAW Dilution :- 20 to 25% Final Layer Final Layer First Layer First Layer E308L E309 E308L E309 POYYARA CONSULTANTS 12 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 POYYARA CONSULTANTS 13 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 Dilution More Thickness Less Thickness POYYARA CONSULTANTS 14 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 Dilution Minimum Overlay Thickness POYYARA CONSULTANTS 15 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 POYYARA CONSULTANTS 16 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 POYYARA CONSULTANTS 17 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 POYYARA CONSULTANTS 19 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 Material Vent Attachment Weld Liner Liner Attachment POYYARA CONSULTANTS 20 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 CS / LAS Base Material Vent Attachment Weld Liner Liner Attachment POYYARA CONSULTANTS 21 Typical Liner Attachment Weld CS / LAS Base Material Vent Attachment Weld Liner Liner Liner Final Layer 1 St Fillet 2 nd Fillet 1 2 3 22 Qualification Requirements For Weld Joints In Clad Material By L D Poyyara POYYARA CONSULTANTS 23 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 Weld Joint Clad Stripping Clad Base Metal Base Metal Butt Weld Final Weld Base Metal Joint Clad Base Metal Clad Restoration – Final Layer 1 2 POYYARA CONSULTANTS 24 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 Base Metal Weld Joint Clad Stripping Clad Base Metal Base Metal Weld Joint OR POYYARA CONSULTANTS 25 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 Clad Stripping Clad Base Metal Base Metal – Without Cladding Base Metal For Welding Qualification – Weld Overlay / Clad Restoration OR Base Metal – With Cladding POYYARA CONSULTANTS 26 Qualification For Weld Overlay / Clad Restoration 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 POYYARA CONSULTANTS 27 Qualification For Weld Overlay / Clad Restoration Test Coupon For Qualification of Weld Overlay / Clad Restoration OR Base Metal – Without Cladding Clad Stripping Clad Base Metal – With Cladding 37 mm min 37 mm min POYYARA CONSULTANTS 28 Qualification For Weld Overlay / Clad Restoration 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 POYYARA CONSULTANTS 29 Qualification For Weld Overlay / Clad Restoration Procedure / Performance Qualification Test Coupon OR Base Metal – Without Cladding Clad Stripping Clad Base Metal – With Cladding 37 mm min 37 mm min Min Job Size – need not > 25 mm Barrier Layer Final Layer Weld Area 37 X 150 mm Min POYYARA CONSULTANTS 30 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. POYYARA CONSULTANTS 31 Procedure Qualification For Weld Overlay / Clad Restoration 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. POYYARA CONSULTANTS 32 Procedure Qualification For Weld Overlay / Clad Restoration Location Of Chemical Analysis & Minimum Thickness Qualified 1 st 2 nd 3 rd X Weld inter Face Base metal Fusion Face 1 st 2 nd 3 rd Weld inter Face Base metal Fusion Face Location of Chips for Chemical Analysis – Depth Minimum Possible X X X = Min. Overlay Thickness Qualified POYYARA CONSULTANTS 33 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 POYYARA CONSULTANTS 34 Procedure Qualification For Weld Overlay / Clad Restoration Procedure Qualification Thickness range – Base metal & Overlay Thickness Of Test Coupon Base metal thickness Qualified Weld Overlay Thickness Min Max Min Max Less Than 25 mm Test Coupon Thickness Any Minimum thickness where chemical analysis found within limit Any Above 25 mm 25 mm Any POYYARA CONSULTANTS 35 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 POYYARA CONSULTANTS 36 Qualification For Weld Overlay / Clad Restoration 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 POYYARA CONSULTANTS 37 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 - 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. POYYARA CONSULTANTS 38 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 POYYARA CONSULTANTS 39 Performance Qualification For Weld Overlay / Clad Restoration Performance Qualification Thickness range – Base metal & Overlay Thickness Of Test Coupon Base metal thickness Qualified Weld Overlay Thickness Min Max Min Max Less Than 25 mm Test Coupon Thickness Any Procedure Qualified Any Above 25 mm 25 mm Any POYYARA CONSULTANTS 40 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 CS / LAS Base Material Vent Attachment Weld Liner Liner Attachment POYYARA CONSULTANTS 41 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 Liner Final Layer