Welded Joint

19 cases · 323 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

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Welded Joint — sub-branches

Cladding 1Fabrication Weld 13In Field Weld 1Remanufacture by Welding 1Repair Weld 1Welded Testpiece for Qualification 2

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Aspect of the cracked valve body, after disassembling and removing the internal parts. The valve is part of a lot that was manufactured by forging a cubic 170mm from a forged bar in SDSS UNS S32760, and heat treated (solution annealed) by the forging company. The fabrication using these bodies included the machining, fillet weld two inserts in Alloy 625, machining again, assembling the internals, and pressure test at 15,000 psi. The cracking occurred during test, only for this valve body.
676
VIEW
ML00134 / Aug.2020
Brittle Fracture of a Superduplex Valve Body
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Fracture
Cm - Aspect Before AnalysisDf - Cracking
Micrographic detail of the weld metal with islands of a coarse ferritic structure, degradated (recristalized) from an acicular morphology during to the long heat treatment cycle in high temperature. The post welding heat treatment (PWHT) was conducted during 12 hours at 640°C.
700
VIEW
ML00129 / Apr.2018
Non qualified WPS for High Strength Steel
M - Low Alloy Medium Carbon QTP - Welded Testpiece for QualificationAp - Oil and GasCd - Non qualified
Cm - Nital Etched Micrography by OMDf - Coarse Structure
Micrography of the tubing fusion line. The welding was conducted in two passes. The average hardness at the heat affected zone of the tubing is 257 HV5.
825
VIEW
ML00100 / Nov.2017
Superduplex Tubing to Forging Welded Joint
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Welding
Cm - NaOH Electrolytic Etched MicroDf - Fusion Line Left Side
Micrographic detail of the fatigue cracking at the margin of the flange to shell fillet weld.
485
VIEW
ML00050 / Nov.2017
Fatigue Failure of a 316SS Pressure Stabilizer
M - Austenitic Stainless SteelP - Fabrication WeldAp - Chemical IndustryCd - Mechanical Fatigue
Cm - Micrography by OM using A262 Method ADf - Fatigue Crack
Draft of the completion riser after removal of the external case showing the hydraulic line position where the 316 tubing is welded by orbital autogenous GTAW to the Nitronic fitting (stab). In the design of these hydraulic lines, the position of the cracking in the fitting is associated to a slightly bent condition of the fitting due to the misaligment of the tubing axis and the stab axis in the connector, visible in the draft.
1082
VIEW
ML00095 / Sep.2017
MIC of a Riser Control Line
M - Austenitic Stainless SteelP - Fabrication WeldAp - Oil and GasCd - Brittle Behavior
Cm - Identification drawingDf - General View
Aspect of the fitting welded to a tubing, ND 5/8" in a hydraulic line. The through wall cracking is longitudinal in the fitting side.
1032
VIEW
ML00094 / Sep.2017
MIC of a Subsea Hydraulic Line
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Behavior
Cm - Aspect Before AnalysisDf - General View
The macrography of a longitudinal section of the pipe and connector, at the welded joint, shows that the welding was conducted from both side of the groove, starting from the ID and finishing from the OD, ID later machined flush. The cracking was detected by ultrasonic test and the macro shows that it is at the fusion line, growthing into the weld metal. See the schematic drawing in the next figure
535
VIEW
ML00072 / Jan.2018
Liquation Cracks in a High Strength Joint
M - Low Alloy Medium Carbon QTP - Longitudinal Seam Welded PipeAp - O&G Well DrillingCd - Welding Defect
Cm - NItal Etched MacroDf - Longitudinal Section
The 8" ND, 1 1/4" thick, seamless pipe that was welded by GMAW process in 6G position. The testpiece was adopted for ASME IX qualification tests.
403
VIEW
ML00066 / May.2017
GMAW Welded Joint in 9%Ni Alloy Steel
M - Nickel Alloy SteelP - Welded Testpiece for QualificationAp - PipelineCd - Welding
Cm - Aspect Before AnalysisDf - Welded Joint

More from these cases

ML00134 — Brittle Fracture of a Superduplex Valve BodyM - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Fracture
Detailed aspect of the cracking, straight and presenting a brittle aspect.
122
VIEW
ML00134 / Aug.2020
Brittle Fracture of a Superduplex Valve Body
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Fracture
Cm - Aspect Before AnalysisDf - Cracking
Detail of the internal bore, showing a brittle crack through the wall.
106
VIEW
ML00134 / Aug.2020
Brittle Fracture of a Superduplex Valve Body
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Fracture
Cm - Aspect Before AnalysisDf - Cracking
Aspect of a section cut transverse to the center of the body. The crack is brittle, trough wall, and was arrested in the region where the valve body was welded to the insert.
105
VIEW
ML00134 / Aug.2020
Brittle Fracture of a Superduplex Valve Body
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Fracture
Cm - Transverse Section AspectDf - Cracking
Microstructural analysis of the valve body structure, close to the position where the cracking has occurred. The structure is ferritic austenitic, with a large amount of detrimental phases associated to the ferritic structure, probably sigma phase.
106
VIEW
ML00134 / Aug.2020
Brittle Fracture of a Superduplex Valve Body
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Fracture
Cm - NaOH Electrolytic Etched MicroDf - Sigma
Micrographic detail of the valve body structure, close to the position where the cracking has occurred. The structure is ferritic austenitic, with a large amount of detrimental phases associated to the ferritic structure, probably sigma phase.
102
VIEW
ML00134 / Aug.2020
Brittle Fracture of a Superduplex Valve Body
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Fracture
Cm - NaOH Electrolytic Etched MicroDf - Sigma

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ML00129 — Non qualified WPS for High Strength SteelM - Low Alloy Medium Carbon QTP - Welded Testpiece for QualificationAp - Oil and GasCd - Non qualified
Micrography of the weld metal, at the face, presenting regions of large ferritic grains. The acicular ferrite structure in the columnar (previous austenitic) grains has suffered degradation due to the long heat treatment cycle (12 hours) in high temperature.
97
VIEW
ML00129 / Apr.2018
Non qualified WPS for High Strength Steel
M - Low Alloy Medium Carbon QTP - Welded Testpiece for QualificationAp - Oil and GasCd - Non qualified
Cm - Nital Etched Micrography by OMDf - Weld Metal
Micrography of the weld metal, at the face, presenting regions of large ferritic grains. The acicular ferrite has suffered degradation due to the long heat treatment cycle (12 hours) in a temperature of 640°C, that is higher than the recommended for the D2 filler metal.
78
VIEW
ML00129 / Apr.2018
Non qualified WPS for High Strength Steel
M - Low Alloy Medium Carbon QTP - Welded Testpiece for QualificationAp - Oil and GasCd - Non qualified
Cm - Nital Etched Micrography by OMDf - Weld Metal
Macrography of the welded joint taken from the vertical up part of the joint, presenting the root in one pass, the fill of the joint in three passes, the cap in three passes and two temper bead passes. The 10" diameter tube, 9.5mm thick, was welded by GTAW in the root (80SD2 filler metal) and by SMAW for fill, cap and temper bead passes (10018-D2 filler metal).
78
VIEW
ML00129 / Apr.2018
Non qualified WPS for High Strength Steel
M - Low Alloy Medium Carbon QTP - Welded Testpiece for QualificationAp - Oil and GasCd - Non qualified
Cm - NItal Etched MacroDf - Welded Joint
WPS welded in 6G qualification welding position and tested according to ASME IX and NACE ISO 15156. Minimum preheating of 250°C. Two temper bead passes. PWHT at 640°C during 12 hours. Tube diameter 10". Thickness 3/8". V groove 70°. Root opening 1/8". NOT APPROVED due to ULTIMATE STRENGHT lower than the base metal minimum requirements.
87
VIEW
ML00129 / Apr.2018
Non qualified WPS for High Strength Steel
M - Low Alloy Medium Carbon QTP - Welded Testpiece for QualificationAp - Oil and GasCd - Non qualified
Cm - WPS summaryDf - Welded Joint
Aspect of the internal surface of the tube, presenting the aspect of the root, after welding and heat treatment.
63
VIEW
ML00129 / Apr.2018
Non qualified WPS for High Strength Steel
M - Low Alloy Medium Carbon QTP - Welded Testpiece for QualificationAp - Oil and GasCd - Non qualified
Cm - Aspect Before AnalysisDf - Internal Surface

+16 more from this case →

ML00100 — Superduplex Tubing to Forging Welded JointM - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Welding
Micrography of the tubing heat affected zone.
69
VIEW
ML00100 / Nov.2017
Superduplex Tubing to Forging Welded Joint
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Welding
Cm - NaOH Electrolytic Etched MicroDf - HAZ Left Side
Micrography of the tubing heat affected zone.
68
VIEW
ML00100 / Nov.2017
Superduplex Tubing to Forging Welded Joint
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Welding
Cm - NaOH Electrolytic Etched MicroDf - HAZ Left Side
Macrography of the welded joint between a forging connector (right side) and a seamless tubing (left side). It was welded in two passes by GTAW process.
168
VIEW
ML00100 / Nov.2017
Superduplex Tubing to Forging Welded Joint
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Welding
Cm - NaOH Electrolytic Etched MacroDf - Welded Joint
Low magnification micrography of the superduplex stainless steel tubing (base metal), in the longitudinal direction. Refined ferritic-austenitic structure. The average hardness in the section is 264HV5.
58
VIEW
ML00100 / Nov.2017
Superduplex Tubing to Forging Welded Joint
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Welding
Cm - NaOH Electrolytic Etched MicroDf - Base Metal Left Side
Micrography of the superduplex stainless steel tubing (base metal), in the longitudinal direction. Refined ferritic-austenitic structure.
55
VIEW
ML00100 / Nov.2017
Superduplex Tubing to Forging Welded Joint
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Welding
Cm - NaOH Electrolytic Etched MicroDf - Duplex structure

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ML00050 — Fatigue Failure of a 316SS Pressure StabilizerM - Austenitic Stainless SteelP - Fabrication WeldAp - Chemical IndustryCd - Mechanical Fatigue
Aspect of the equipment presenting a through wall cracking at the margin of the fillet weld.
143
VIEW
ML00050 / Nov.2017
Fatigue Failure of a 316SS Pressure Stabilizer
M - Austenitic Stainless SteelP - Fabrication WeldAp - Chemical IndustryCd - Mechanical Fatigue
Cm - Aspect Before AnalysisDf - Cracking
Macrography of the welded joint between the flange and the shell, indicating the position where the cracking was detected, at 90°.
117
VIEW
ML00050 / Nov.2017
Fatigue Failure of a 316SS Pressure Stabilizer
M - Austenitic Stainless SteelP - Fabrication WeldAp - Chemical IndustryCd - Mechanical Fatigue
Cm - Macro Oxalic Acid Electrolytic EtchedDf - Welded Joint
The shell plate micrography showed an austenitic structure.
101
VIEW
ML00050 / Nov.2017
Fatigue Failure of a 316SS Pressure Stabilizer
M - Austenitic Stainless SteelP - Fabrication WeldAp - Chemical IndustryCd - Mechanical Fatigue
Cm - Micrography by OM using A262 Method ADf - Austenite
The macrography of a transverse section of the shell to flange weld (Lepto's etch) shows that the cracking occurred through the shell plate thickness, at the margin of the fillet weld.
93
VIEW
ML00050 / Nov.2017
Fatigue Failure of a 316SS Pressure Stabilizer
M - Austenitic Stainless SteelP - Fabrication WeldAp - Chemical IndustryCd - Mechanical Fatigue
Cm - Transverse Section AspectDf - Cracking
Fracture surface after opening the shell cracking, presenting fatigue striation. The fracture presents also foreign particles.
132
VIEW
ML00050 / Nov.2017
Fatigue Failure of a 316SS Pressure Stabilizer
M - Austenitic Stainless SteelP - Fabrication WeldAp - Chemical IndustryCd - Mechanical Fatigue
Cm - Fractography by SEMDf - Fatigue Striation

+3 more from this case →

ML00095 — MIC of a Riser Control LineM - Austenitic Stainless SteelP - Fabrication WeldAp - Oil and GasCd - Brittle Behavior
Aspect of the hydraulic line samples removed from service to be analyzed. Tubing and welded joint (bottom sample) between the 316 tubing (left side of the sample) and the nitronic fitting (right side of the sample). The cracking is located 10 mm far from the weld, autogenous orbital GTAW.
108
VIEW
ML00095 / Sep.2017
MIC of a Riser Control Line
M - Austenitic Stainless SteelP - Fabrication WeldAp - Oil and GasCd - Brittle Behavior
Cm - Aspect Before AnalysisDf - General View
Scanning electron microscopy image of the external surface of the line at the cracking position showing multiple cracks, branched, transverse to the line axis.
79
VIEW
ML00095 / Sep.2017
MIC of a Riser Control Line
M - Austenitic Stainless SteelP - Fabrication WeldAp - Oil and GasCd - Brittle Behavior
Cm - Surface Aspect by SEMDf - External Surface
Detail, by scanning electron microscopy, of the external surface of the line at the cracking position presenting branched cracks, transverse to the line axis. The surface of the fitting is fully stained (dark grey), from where the cracks start, indicating that the material loose passivation in these regions.
62
VIEW
ML00095 / Sep.2017
MIC of a Riser Control Line
M - Austenitic Stainless SteelP - Fabrication WeldAp - Oil and GasCd - Brittle Behavior
Cm - Surface Aspect by SEMDf - Branched Cracks
Detail of the welded joint between the 316 tubing (left side) and the nitronic fitting (right side). The through wall cracking is transverse to the line, in the fitting, 10 mm far from the weld, where the fitting was slightly bent to be assembled (cold bent).
65
VIEW
ML00095 / Sep.2017
MIC of a Riser Control Line
M - Austenitic Stainless SteelP - Fabrication WeldAp - Oil and GasCd - Brittle Behavior
Cm - Aspect Before AnalysisDf - Welded Joint
The longitudinal section macrography of the welded joint sample shows that the cracks are positioned in the fitting, about 10 mm far from the weld.
60
VIEW
ML00095 / Sep.2017
MIC of a Riser Control Line
M - Austenitic Stainless SteelP - Fabrication WeldAp - Oil and GasCd - Brittle Behavior
Cm - Macro Oxalic Acid Electrolytic EtchedDf - Longitudinal Section

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ML00094 — MIC of a Subsea Hydraulic LineM - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Behavior
Detail of the longitudinal through wall cracking in the fitting welded to a tubing, ND 5/8" in a hydraulic line.
87
VIEW
ML00094 / Sep.2017
MIC of a Subsea Hydraulic Line
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Behavior
Cm - Aspect Before AnalysisDf - External Surface
Macrography of a longitudinal section of the fitting to tubing weld, with the longitudinal cracking at the tubular fitting position.
69
VIEW
ML00094 / Sep.2017
MIC of a Subsea Hydraulic Line
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Behavior
Cm - Kalling Etched MacroDf - Longitudinal Section
Aspect of the internal side of the fitting to tubing welded joint, after longitudinal cut. It is possible to see that the cracking (still filled with corrosion products) is located in the fitting side (left side) far from the welded joint to the tubing (right side).
58
VIEW
ML00094 / Sep.2017
MIC of a Subsea Hydraulic Line
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Behavior
Cm - Aspect Before AnalysisDf - Internal Surface
Aspect of the internal side of the fitting, at the cracked position with corrosion products and several surface microcracks adjacent to the main crack.
52
VIEW
ML00094 / Sep.2017
MIC of a Subsea Hydraulic Line
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Behavior
Cm - Surface AspectDf - Internal Surface
Aspect by scanning electron microscopy of the cracking at the external surface of the fitting.
47
VIEW
ML00094 / Sep.2017
MIC of a Subsea Hydraulic Line
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Behavior
Cm - Surface Aspect by SEMDf - External Surface

+13 more from this case →

ML00072 — Liquation Cracks in a High Strength JointM - Low Alloy Medium Carbon QTP - Longitudinal Seam Welded PipeAp - O&G Well DrillingCd - Welding Defect
Schematic drawing presenting the longitudinal section of the pipe and connector at the welded joint
105
VIEW
ML00072 / Jan.2018
Liquation Cracks in a High Strength Joint
M - Low Alloy Medium Carbon QTP - Longitudinal Seam Welded PipeAp - O&G Well DrillingCd - Welding Defect
Cm - Identification drawingDf - Longitudinal Section
Hot cracking at the fusion line of the connector side, in a welded joint between a forging and a pipe, in a macrographic sample. The region of the heat affected zone of the connector presents a dendritic aspect suggesting that the forging reduction rate of the connector was not too high and did not broke the cast structure.
110
VIEW
ML00072 / Jan.2018
Liquation Cracks in a High Strength Joint
M - Low Alloy Medium Carbon QTP - Longitudinal Seam Welded PipeAp - O&G Well DrillingCd - Welding Defect
Cm - NItal Etched MacroDf - Welded Joint
The connector was welded to the pipe from both (internal and external) sides, a PWHT was applied and the part was machined. The UT indication was detected during final inspection.
78
VIEW
ML00072 / Jan.2018
Liquation Cracks in a High Strength Joint
M - Low Alloy Medium Carbon QTP - Longitudinal Seam Welded PipeAp - O&G Well DrillingCd - Welding Defect
Cm - Aspect Before AnalysisDf - General View
Micrography of the welded joint fusion line presenting the liquation cracking. The weld metal is in the right side (bottom) and the forged connector heat affected zone is in the left side (top).
83
VIEW
ML00072 / Jan.2018
Liquation Cracks in a High Strength Joint
M - Low Alloy Medium Carbon QTP - Longitudinal Seam Welded PipeAp - O&G Well DrillingCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Cracking
The liquation crack is a hot crack in the base metal (at the HAZ) that induces a solidification crack in the weld metal.
66
VIEW
ML00072 / Jan.2018
Liquation Cracks in a High Strength Joint
M - Low Alloy Medium Carbon QTP - Longitudinal Seam Welded PipeAp - O&G Well DrillingCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Weld Metal

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ML00066 — GMAW Welded Joint in 9%Ni Alloy SteelM - Nickel Alloy SteelP - Welded Testpiece for QualificationAp - PipelineCd - Welding
Transversal section of the 625 nickel alloy multipass weld. Pipe of 1 1/4' thickness
72
VIEW
ML00066 / May.2017
GMAW Welded Joint in 9%Ni Alloy Steel
M - Nickel Alloy SteelP - Welded Testpiece for QualificationAp - PipelineCd - Welding
Cm - NItal Etched MacroDf - Welded Joint
Schematic drawing presenting the transversal section of the 625 nickel alloy multipass weld
56
VIEW
ML00066 / May.2017
GMAW Welded Joint in 9%Ni Alloy Steel
M - Nickel Alloy SteelP - Welded Testpiece for QualificationAp - PipelineCd - Welding
Cm - Identification drawingDf - Welded Joint
Micrography of the base metal presenting a banded microstructure in the longitudinal section of the pipe.
52
VIEW
ML00066 / May.2017
GMAW Welded Joint in 9%Ni Alloy Steel
M - Nickel Alloy SteelP - Welded Testpiece for QualificationAp - PipelineCd - Welding
Cm - Nital Etched Micrography by OMDf - Base Metal
Micrographic detail of a longitudinal section of the base metal presenting a quenched and tempered microstructure.
50
VIEW
ML00066 / May.2017
GMAW Welded Joint in 9%Ni Alloy Steel
M - Nickel Alloy SteelP - Welded Testpiece for QualificationAp - PipelineCd - Welding
Cm - Nital Etched Micrography by OMDf - Base Metal
Micrographic detail of the low temperature heat affected zone of the pipe. The intercritical temperature (IC) is evident in the decorated grain boundaries of the previous austenite.
43
VIEW
ML00066 / May.2017
GMAW Welded Joint in 9%Ni Alloy Steel
M - Nickel Alloy SteelP - Welded Testpiece for QualificationAp - PipelineCd - Welding
Cm - Nital Etched Micrography by OMDf - Heat Affected Zone

+11 more from this case →