Naked Eye or Stereoscope

8 cases · 28 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Microstructure: Duplex Ferritic Austenitic clear all

Naked Eye or Stereoscope — sub-branches

Electrolytically Etched Macro 2Fracture Surface Aspect 2Kalling Etched Macro 2Longitudinal Section Aspect 3NaOH Electrolytic Etched Macro 13Surface Aspect 3Transverse Section Aspect 3

Results

SortNewestOldestTitle A-ZTitle Z-A
Macrography of the section transverse to the ND 14" main pipe (that is only 5mm thick) and to the ND 2" branch that is a weldolet fitting welded to the main pipe and flange. This image is interesting because it shows clearly how thin is the pipe compared with the fitting thickness and the large amount of welding required to assure a full penetration weld in the weldolet.
220
VIEW
ML00150 / Dec.2018
Vibration Induced Fatigue in a SS Oil Piping
M - Duplex Stainless SteelP - PipingAp - FPSOCd - Vibration Induced Fatigue
Cm - NaOH Electrolytic Etched MacroDf - Transverse Section
Detail of the external surface of the sleeve where the surface coating was detached, creating a lack of sealing condition.
67
VIEW
ML00147 / Aug.2018
WC Layer Detached from a Cast Lean Duplex
M - Lean Duplex Stainless SteelP - Centrifugal CastingAp - ShipCd - Lack of Sealing
Cm - Surface AspectDf - External Surface
The longitudinal section of the pin shows that it was deformed in a localized position, where the layer was detached, top side of the figure. The pin wall was plastically deformed decreasing the internal diameter.
222
VIEW
ML00146 / Jul.2018
Plastic Deformation of a SDSS Riser Pin
M - Super Duplex Stainless SteelP - PinAp - O&G Well DrillingCd - Bending
Cm - Longitudinal Section AspectDf - Plastic Deformation
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
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
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
Macrography of the pipe to flange weld. Transverse section identifying the regions of the base materials, heat affected zones and weld metal, which microstructures are presented in this ML.
527
VIEW
ML00049 / Apr.2017
Pipe to Flange Welded Joint in a 14" ND Superduplex Spool
M - Super Duplex Stainless SteelP - Piping spoolAp - Oil and GasCd - Removed From Service
Cm - NaOH Electrolytic Etched MacroDf - Welded Joint
Macrography of a longitudinal section of the flange to pipe weld, cracked in the flange. Pipe thickness, measured, is 5 mm. Flange thickness at the welded region is 7.5 mm. The macro was etched using NaOH solution, electrolytic.
181
VIEW
ML00002 / Jan.2018
Preferential Dissolution and Cracks in SDSS
M - Super Duplex Stainless SteelP - Fabrication WeldAp - PipingCd - Preferential Dissolution
Cm - NaOH Electrolytic Etched MacroDf - Longitudinal Section

More from these cases

ML00150 — Vibration Induced Fatigue in a SS Oil PipingM - Duplex Stainless SteelP - PipingAp - FPSOCd - Vibration Induced Fatigue
Transverse section of the 14" pipe in the center of the 2" branch using a weldolet fitting welded to the main pipe. The internal side of the pipe is to the top of the figure and the through wall fatigue cracking is located at the margem of the weld. It is possible to see that it is a full penetration weld and the fitting thickness is several times larger than the pipe thickness.
174
VIEW
ML00150 / Dec.2018
Vibration Induced Fatigue in a SS Oil Piping
M - Duplex Stainless SteelP - PipingAp - FPSOCd - Vibration Induced Fatigue
Cm - Electrolytically Etched MacroDf - Crack
Detail of the fatigue cracking, staring from the margin of the weld. The crack propagated though wall of the pipe (5 mm). The larger thickness of the weldolet requires a large amount of deposited weld metal, about 20 mm that is 4 times the pipe thickness. It is an interesting aspect to be considered by designers.
176
VIEW
ML00150 / Dec.2018
Vibration Induced Fatigue in a SS Oil Piping
M - Duplex Stainless SteelP - PipingAp - FPSOCd - Vibration Induced Fatigue
Cm - Electrolytically Etched MacroDf - Fatigue Crack
After cutting the pipe and opening the crack, the fracture appearance shows a clean fracture, flat, starting from the margem of the weld of the pipe (right side of the figure), and propagating through wall into the pipe (aproximately 5 mm thickness). The external side of the pipe is to the right side of the figure (presenting the weld finishing) and the internal side of the pipe is to the left side of the figure.
176
VIEW
ML00150 / Dec.2018
Vibration Induced Fatigue in a SS Oil Piping
M - Duplex Stainless SteelP - PipingAp - FPSOCd - Vibration Induced Fatigue
Cm - Fracture Surface AspectDf - Fracture
Macrographic detail of the pipe to weldolet weld, and the through wall cracking in the pipe from the margin of the weld. The pipe thickness is only 5 mm (SCH 10S) but the large thickness of the fitting required several weld passes to create a full penetration weld.
84
VIEW
ML00150 / Dec.2018
Vibration Induced Fatigue in a SS Oil Piping
M - Duplex Stainless SteelP - PipingAp - FPSOCd - Vibration Induced Fatigue
Cm - NaOH Electrolytic Etched MacroDf - Welded Joint
Macrography of a transverse section of the welded joint, at the fatigue crack position in the pipe. It is very interesting to observe that the crack propagated from the margin of the weld, independently of the defects in the weld (porosity and lack of fusion), and without relationship with the unbalanced structure at the cap (with a large amount of ferrite). These characteristics are detailed in the next figures.
89
VIEW
ML00150 / Dec.2018
Vibration Induced Fatigue in a SS Oil Piping
M - Duplex Stainless SteelP - PipingAp - FPSOCd - Vibration Induced Fatigue
Cm - NaOH Electrolytic Etched MacroDf - Welded Joint
ML00147 — WC Layer Detached from a Cast Lean DuplexM - Lean Duplex Stainless SteelP - Centrifugal CastingAp - ShipCd - Lack of Sealing
Longitudinal slice of the flanged sleeve, 180 mm long, in a macrography presenting the 1/2" tubular wall thickness where the sealing was applied. The external surface of the sleeve (seawater wet) is in the left side of the figure and the internal surface (oiled) is in the right side. The flange is to the top of the figure.
52
VIEW
ML00147 / Aug.2018
WC Layer Detached from a Cast Lean Duplex
M - Lean Duplex Stainless SteelP - Centrifugal CastingAp - ShipCd - Lack of Sealing
Cm - Longitudinal Section AspectDf - General View
Macrographic aspect of the sleeve longitudinal section where the coating was applied in the external side (top of the figure). It is possible to see that the sleeve was manufactured by centrifugal casting, with elongated grains from the external side, and equiaxial grains close to the internal side (bottom of the figure). There is a weaved interface between the sleeve and the first layer of thermal spray coating, 1 mm thick; and a second layer of thermal spray coating, 0.2mm thick (almost imperceptible at this low magnification).
49
VIEW
ML00147 / Aug.2018
WC Layer Detached from a Cast Lean Duplex
M - Lean Duplex Stainless SteelP - Centrifugal CastingAp - ShipCd - Lack of Sealing
Cm - NaOH Electrolytic Etched MacroDf - Coating Layer
Macroscopic aspect of the OD surface of the sleeve (top of the figure), and a macrography of a longitudinal section (bottom of the figure). In the right side of the figure it is possible to see that the lack of sealing is associated to the detachment of the thermal spray surface layer.
26
VIEW
ML00147 / Aug.2018
WC Layer Detached from a Cast Lean Duplex
M - Lean Duplex Stainless SteelP - Centrifugal CastingAp - ShipCd - Lack of Sealing
Cm - Surface AspectDf - Longitudinal Section
Macrography of a longitudinal section showing the region where the surface layer was detached (top of the figure), creating a lack of sealing condition.
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 - NaOH Electrolytic Etched MacroDf - Thermal Spray Layer
ML00146 — Plastic Deformation of a SDSS Riser PinM - Super Duplex Stainless SteelP - PinAp - O&G Well DrillingCd - Bending
The longitudinal section of the pin at the region of the thermal spray layer detachment, showing that the pin suffered a localized lateral bending with strong plastic deformation, responsible for the layer detachment. The figure shows the external surface (top of the figure) with the layer detachment (gray aspect), the thickness of the pin (deformed) and the internal surface (bright aspect).
124
VIEW
ML00146 / Jul.2018
Plastic Deformation of a SDSS Riser Pin
M - Super Duplex Stainless SteelP - PinAp - O&G Well DrillingCd - Bending
Cm - Longitudinal Section AspectDf - Plastic Deformation
ML00134 — Brittle Fracture of a Superduplex Valve BodyM - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Fracture
Aspect of a section cut transverse to the center of the body. The structure of the valve body was not uniform and close to the BX groove body face the structure was more degradated than in the bottom of the body, as it will be presented in the next figures.
83
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
Aspect of a section cut transverse to the center of the body. The cracking is brittle, trough wall.
58
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
Aspect of the fracture surface after cutting the valve body and opening the crack. The fracture is brittle.
55
VIEW
ML00134 / Aug.2020
Brittle Fracture of a Superduplex Valve Body
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Fracture
Cm - Fracture Surface AspectDf - Brittle Fracture
Aspect of the valve body after cutting a slice containg the crack and the welded joint of the body to the insert (fillet weld). The cracking was arrested at the position of this welded joint.
56
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 MacroDf - Welded Joint
Macrographic detail of the valve at the welded joint of the SDSS body (left side of the figure) to the Alloy 625 insert (right side of the figure), by a fillet weld. The cracking was arrested at the position of this welded joint.
49
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 MacroDf - Welded Joint
ML00094 — MIC of a Subsea Hydraulic LineM - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Behavior
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
Macrography of the fitting to tubing welded joint. The internal surface of the fitting (left side) is rough compared to the internal surface of the tubing (right side). The cracking is located only in the fitting and presented no association with the welded joint.
41
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
ML00049 — Pipe to Flange Welded Joint in a 14" ND Superduplex SpoolM - Super Duplex Stainless SteelP - Piping spoolAp - Oil and GasCd - Removed From Service
Macrography of the pipe heat affected zone.
55
VIEW
ML00049 / Apr.2017
Pipe to Flange Welded Joint in a 14" ND Superduplex Spool
M - Super Duplex Stainless SteelP - Piping spoolAp - Oil and GasCd - Removed From Service
Cm - NaOH Electrolytic Etched MacroDf - Heat Affected Zone
Macrography of the flange HAZ. The macroscopic aspect shows a remarkable modified region.
56
VIEW
ML00049 / Apr.2017
Pipe to Flange Welded Joint in a 14" ND Superduplex Spool
M - Super Duplex Stainless SteelP - Piping spoolAp - Oil and GasCd - Removed From Service
Cm - NaOH Electrolytic Etched MacroDf - Heat Affected Zone
Micrographic detail of the center of the weld metal (fill pass). Duplex ferritic austenitic structure.
27
VIEW
ML00049 / Apr.2017
Pipe to Flange Welded Joint in a 14" ND Superduplex Spool
M - Super Duplex Stainless SteelP - Piping spoolAp - Oil and GasCd - Removed From Service
Cm - NaOH Electrolytic Etched MacroDf - Weld Metal in the Center