Damage

6 cases · 16 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Microstructure: Duplex Ferritic Austenitic Capture method: Aspect Before Analysis clear all

Damage — sub-branches

Brittle Behavior 1Corrosion 2Ductile Behavior 1Fabrication Defect 1Fatigue 1Lack of Sealing 1

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Vertical piping in a corrosive oil producing system of a FPSO. The line is a nominal diameter 14" sch 10S (pipe thickness about 5 mm) and the flanged branch line is a 2" nominal diameter welded to the main pipe using a weldolet (forged fitting). The fatigue induced cracking occurred longitudinal to the main pipe, originated at the margem of the weld interface with the pipe.
1480
VIEW
ML00150 / Dec.2018
Vibration Induced Fatigue in a SS Oil Piping
M - Duplex Stainless SteelP - PipingAp - FPSOCd - Vibration Induced Fatigue
Cm - Aspect Before AnalysisDf - General View
Macroscopic aspect of the outer diameter of the flanged sleeve presenting adhered products at the surface. The flanged sleeve was manufactured by centrifugal casting in a lean duplex stainless steel and it was externally coated by thermal spray (TS) in a position of sealing. After 5 years in service the system suffered leakage.
569
VIEW
ML00147 / Aug.2018
WC Layer Detached from a Cast Lean Duplex
M - Lean Duplex Stainless SteelP - Centrifugal CastingAp - ShipCd - Lack of Sealing
Cm - Aspect Before AnalysisDf - External Surface
Aspect of the male part of the coupling, a pin, presenting the thermal spray layer detachment (right side of the figure). The pin was manufactured in a superduplex stainless steel tubular forging; the external surface was partially coated by thermal spray and machined. The sealing is only elastomeric but a coating is required to avoid galling between the two materials of the coupling.
1154
VIEW
ML00146 / Jul.2018
Plastic Deformation of a SDSS Riser Pin
M - Super Duplex Stainless SteelP - PinAp - O&G Well DrillingCd - Bending
Cm - Aspect Before AnalysisDf - Layer Detachment
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
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
Visual aspect from the external side of the 14"ND flange butt welded to a pipe, presenting a through wall crack about 5mm to 10mm from the butt welding.
925
VIEW
ML00002 / Jan.2018
Preferential Dissolution and Cracks in SDSS
M - Super Duplex Stainless SteelP - Fabrication WeldAp - PipingCd - Preferential Dissolution
Cm - Aspect Before AnalysisDf - Through Wall Cracking

More from these cases

ML00150 — Vibration Induced Fatigue in a SS Oil PipingM - Duplex Stainless SteelP - PipingAp - FPSOCd - Vibration Induced Fatigue
Duplex stainless steel piping, in a region where the 14" ND pipe is only 5mm thick and the branch is a weldolet (forged fitting) welded to the pipe and to the flange, a lot more thicker than the pipe.
107
VIEW
ML00150 / Dec.2018
Vibration Induced Fatigue in a SS Oil Piping
M - Duplex Stainless SteelP - PipingAp - FPSOCd - Vibration Induced Fatigue
Cm - Aspect Before AnalysisDf - General View
ML00147 — WC Layer Detached from a Cast Lean DuplexM - Lean Duplex Stainless SteelP - Centrifugal CastingAp - ShipCd - Lack of Sealing
General view of the 10" diameter flanged sleeve, 1/2" wall thickness, manufactured by centrifugal casting of lean duplex stainless steel (DSS), Alloy 2304 (without Mo), with an external coating applied by thermal spray (TS). The sleeve is assembled in a shaft. The internal environment is oil and a seal box is assembled in the external side that is wet with seawater.
56
VIEW
ML00147 / Aug.2018
WC Layer Detached from a Cast Lean Duplex
M - Lean Duplex Stainless SteelP - Centrifugal CastingAp - ShipCd - Lack of Sealing
Cm - Aspect Before AnalysisDf - General View
General view of the 10" diameter flanged sleeve, with the external coating applied by thermal spray (TS), and the sealing rings of the seal box assembled at the sleeve external surface. It is important to observe that the internal surface of the sleeve presents no corrosion spots.
23
VIEW
ML00147 / Aug.2018
WC Layer Detached from a Cast Lean Duplex
M - Lean Duplex Stainless SteelP - Centrifugal CastingAp - ShipCd - Lack of Sealing
Cm - Aspect Before AnalysisDf - General View
General view of the 10" diameter flanged sleeve, with the sealing rings of the seal box assembled at the sleeve external surface. The right side of the figure shows the surface region where the a lack of seal was identified, with adhered products.
23
VIEW
ML00147 / Aug.2018
WC Layer Detached from a Cast Lean Duplex
M - Lean Duplex Stainless SteelP - Centrifugal CastingAp - ShipCd - Lack of Sealing
Cm - Aspect Before AnalysisDf - External Surface
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
Image of the external surface of the valve body at the region where the Alloy 625 insert was fillet weld to the SDSS valve body. The surface was later machined, so it is possible to see only a mark indicating where the weld is. The brittle crack is arrested at the margin of the weld. It is possible to see strong deformation at the crack tip when it arrives the weld.
41
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 - External Surface
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
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
ML00002 — Preferential Dissolution and Cracks in SDSSM - Super Duplex Stainless SteelP - Fabrication WeldAp - PipingCd - Preferential Dissolution
After a longitudinal section of the flange to pipe weld, the through wall cracking opened in two parts and the fracture surface was analyzed. The flange side fracture surface is presented in this figure.
126
VIEW
ML00002 / Jan.2018
Preferential Dissolution and Cracks in SDSS
M - Super Duplex Stainless SteelP - Fabrication WeldAp - PipingCd - Preferential Dissolution
Cm - Aspect Before AnalysisDf - Fracture