Naked Eye or Stereoscope

23 cases · 57 images for “corrosion”

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Naked Eye or Stereoscope — sub-branches

Fracture Surface Aspect 1Kalling Etched Macro 3Keller Etched Macro 2Longitudinal Section Aspect 2Macro Oxalic Acid Electrolytic Etched 6NItal Etched Macro 11Surface Aspect 17Transverse Section Aspect 15

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Throught wall cracking of the waterwall tube at the leakage position, thick edged, The external surface of the tube was grounded to remove the membrane and the cracking is associated to the tube attachement.
242
VIEW
ML00163 / Jun.2020
Corrosion Fatigue of a Boiler Waterwall Tube
M - Low Carbon SteelP - Seamless tubeAp - BoilerCd - Corrosion Fatigue
Cm - Transverse Section AspectDf - Thick-edged rupture
Aspect of a transverse section of the 4" pipe showing the barnacles adhered to the internal pipe surface, and the leakage position (in the top of the figure). It is possible to see that the deposits are attached all throught the internal pipe perimeter but the damage is localized. The damage morphology suggests it is a crack, or a welding defect, but the microstructural analysis indicated that the damage is a galvanic effect at the autogenous seam weld.
1135
VIEW
ML00140 / May.2019
Preferential Corrosion of Pipe Seam Weld
M - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Cm - Longitudinal Section AspectDf - Localized Corrosion
After a longitudinal cut of the case it was possible to see that a localized corrosion has occurred associated to the regions where there were sealed holes, plugged, in a crevice condition, not related to any welded position.
193
VIEW
ML00122 / Feb.2018
Crevice Corrosion in a Subsea System
M - Austenitic Stainless SteelP - CaseAp - Oil and GasCd - Crevice
Cm - Transverse Section AspectDf - Corrosion
Nitronic 60 cylinder. Detailed aspect of the pitting in a low magnification microscope.
197
VIEW
ML00121 / Feb.2018
Pitting Corrosion in a Subsea System
M - Austenitic / MartensiticP - Rod & CylinderAp - SubseaCd - Pitting Corrosion
Cm - Surface AspectDf - Pitting
Low magnification microscopy (stereoscope) detail of the multiple cracks at the pin surface.
146
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Surface AspectDf - Multiple cracks
Detail of the internal piping surface, showing lack of deposits and a shinning surface, suggesting erosive conditions.
226
VIEW
ML00065 / May.2017
Erosion Corrosion of Monel Piping
M - NiCu AlloyP - Seamless PipeAp - Chemical IndustryCd - Erosion Corrosion
Cm - Surface AspectDf - Leakage
Aspect of the washout in the 5" drill pipe, in the pipe body, after cleaning the surface. The surface presents several parallel tool marks that are not typical in the pipe since the torque is applied in the tool joint.
195
VIEW
ML00068 / Sep.2020
Corrosion Fatigue of a 5" Drill Pipe
M - Low Alloy Medium Carbon QTP - Seamless PipeAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Surface AspectDf - At the Surface
Internal surface detail of the 3 1/2" pipe, cut in a longitudinal section (transverse to the weld), presenting a localized corrosion at the margin of the welded joint (Keller etched), in the root. The pipeline was assembled with pipes manufactured in two different aluminum alloys, AA 3003 (top of the figure) and AA 6063 (bottom of the figure), and the localized corrosion occurred at the fusion line of the 6063 pipe.
1296
VIEW
ML00059 / Feb.2018
Intergranular Corrosion of Aluminum Piping
M - Aluminum ManganeseP - Welded JointAp - Chemical IndustryCd - Intergranular Corrosion
Cm - Surface AspectDf - Welded Joint

More from these cases

ML00163 — Corrosion Fatigue of a Boiler Waterwall TubeM - Low Carbon SteelP - Seamless tubeAp - BoilerCd - Corrosion Fatigue
Macrography of the transverse section of the tube, in a position where the cracking was not yet through wall. The internal tube surface shows multiple corrosion fatigue cracks, parallel, under the weld of the membrane, probably related to the cold side of the tube (the cracks opened to the boiler outside). The external side of the tube presenting a small crack at the margem of the weld, suggesting also the action of thermal stresses.
214
VIEW
ML00163 / Jun.2020
Corrosion Fatigue of a Boiler Waterwall Tube
M - Low Carbon SteelP - Seamless tubeAp - BoilerCd - Corrosion Fatigue
Cm - NItal Etched MacroDf - Multiple cracks
ML00140 — Preferential Corrosion of Pipe Seam WeldM - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Detail of the transverse section of the 4" pipe at the longitudinal seam weld evidencing the leakage position. The damage appears as a through wall opening. The pipe thickness is 8 mm and there are no evidences of general corrosion (the SCH 80 corresponds to 8.6 mm) or pitting at the internal surface.
100
VIEW
ML00140 / May.2019
Preferential Corrosion of Pipe Seam Weld
M - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Cm - Transverse Section AspectDf - Leakage
Detail of the transverse section of the 4" pipe 90° from the seam weld. The thickness of the pipe is 8 mm. No evidences of general corrosion or pitting were identified.
77
VIEW
ML00140 / May.2019
Preferential Corrosion of Pipe Seam Weld
M - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Cm - Transverse Section AspectDf - Transverse Section
Detail of the transverse section of the 4" pipe 90° from the seam weld. The thickness of the pipe is 8 mm. No evidences of general corrosion or pitting were identified.
70
VIEW
ML00140 / May.2019
Preferential Corrosion of Pipe Seam Weld
M - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Cm - Transverse Section AspectDf - Transverse Section
Detail of the transverse section of the 4" pipe 180° from the seam weld. The thickness of the pipe is 8 mm. No evidences of general corrosion or pitting were identified.
64
VIEW
ML00140 / May.2019
Preferential Corrosion of Pipe Seam Weld
M - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Cm - Transverse Section AspectDf - Transverse Section
Detail of the transverse section of the 4" pipe at the longitudinal seam weld where it is not leaking yet, showing that the damage is not a crack but a localized dissolution, or localized corrosion or preferential dissolution at the autogenous seam weld. The thickness of the pipe is 8 mm and there are no evidences of general corrosion or pitting.
63
VIEW
ML00140 / May.2019
Preferential Corrosion of Pipe Seam Weld
M - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Cm - Transverse Section AspectDf - Localized Corrosion

+2 more from this case →

ML00122 — Crevice Corrosion in a Subsea SystemM - Austenitic Stainless SteelP - CaseAp - Oil and GasCd - Crevice
Macrography of the longitudinal section of the case, that was welded to padeyes. The corrosion occurred in a region where there were no microstructural changes, only the hole that was sealed with a plug and suffered a crevice corrosion mechanism.
145
VIEW
ML00122 / Feb.2018
Crevice Corrosion in a Subsea System
M - Austenitic Stainless SteelP - CaseAp - Oil and GasCd - Crevice
Cm - Macro Oxalic Acid Electrolytic EtchedDf - Corrosion
The macrography of a longitudinal section of the case shows one region where a through wall localized corrosion has occurred (in the left side of the image) and regions where the case was welded to a padeye, without any corrosion damage.
141
VIEW
ML00122 / Feb.2018
Crevice Corrosion in a Subsea System
M - Austenitic Stainless SteelP - CaseAp - Oil and GasCd - Crevice
Cm - Macro Oxalic Acid Electrolytic EtchedDf - Corrosion
Detail of the case thickness (20 mm) with the through wall localized corrosion in a crevice condition where there was a plug.
98
VIEW
ML00122 / Feb.2018
Crevice Corrosion in a Subsea System
M - Austenitic Stainless SteelP - CaseAp - Oil and GasCd - Crevice
Cm - Transverse Section AspectDf - Localized Corrosion
ML00121 — Pitting Corrosion in a Subsea SystemM - Austenitic / MartensiticP - Rod & CylinderAp - SubseaCd - Pitting Corrosion
17-4 PH rod. Detailed aspect of the pitting in a low magnification microscope.
115
VIEW
ML00121 / Feb.2018
Pitting Corrosion in a Subsea System
M - Austenitic / MartensiticP - Rod & CylinderAp - SubseaCd - Pitting Corrosion
Cm - Surface AspectDf - Pitting
17-4 PH rod, tubular, OD 10.6mm, wall thickness about 3.5 mm. Macrography of the rod in a transverse section showing the pitting in a position where it is almost through wall.
86
VIEW
ML00121 / Feb.2018
Pitting Corrosion in a Subsea System
M - Austenitic / MartensiticP - Rod & CylinderAp - SubseaCd - Pitting Corrosion
Cm - Kalling Etched MacroDf - Pitting
ML00065 — Erosion Corrosion of Monel PipingM - NiCu AlloyP - Seamless PipeAp - Chemical IndustryCd - Erosion Corrosion
Macrography of the pipe to fitting welded joint, in a region where the thickness loss is almost uniform. The pipe is in the left of the figure and the elbow is in the right, with a general thinning (average of 2 mm, considering that the original thickness was 3.7 mm), and a slightly more intense thickness loss at the weld metal near the elbow side.
183
VIEW
ML00065 / May.2017
Erosion Corrosion of Monel Piping
M - NiCu AlloyP - Seamless PipeAp - Chemical IndustryCd - Erosion Corrosion
Cm - Kalling Etched MacroDf - Welded Joint
Macrography of the pipe to fitting welded joint, in a region very close to the leakage. The sligthly localized thinning is in the weld metal close to the elbow.
53
VIEW
ML00065 / May.2017
Erosion Corrosion of Monel Piping
M - NiCu AlloyP - Seamless PipeAp - Chemical IndustryCd - Erosion Corrosion
Cm - Kalling Etched MacroDf - Thinning
ML00068 — Corrosion Fatigue of a 5" Drill PipeM - Low Alloy Medium Carbon QTP - Seamless PipeAp - O&G Well DrillingCd - Corrosion Fatigue
The longitudinal section of the 1/2" thick pipe close to the washout position shows that the external tool marks are like notches that are corroded and cracks are iniciating from the corroded regions. The top of the figure presents the external pipe surface and the bottom of the figure presents the internal pipe surface, with a green coating and the rusted washout.
154
VIEW
ML00068 / Sep.2020
Corrosion Fatigue of a 5" Drill Pipe
M - Low Alloy Medium Carbon QTP - Seamless PipeAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - NItal Etched MacroDf - Longitudinal Section
Macrography of the longitudinal section of the pipe presenting multiple cracks from the tool marks.
122
VIEW
ML00068 / Sep.2020
Corrosion Fatigue of a 5" Drill Pipe
M - Low Alloy Medium Carbon QTP - Seamless PipeAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - NItal Etched MacroDf - Cracks Transverse to the Surface
ML00059 — Intergranular Corrosion of Aluminum PipingM - Aluminum ManganeseP - Welded JointAp - Chemical IndustryCd - Intergranular Corrosion
The macrography of the welded joint shows the AA 6063 alloy pipe in the right and the AA 3003 pipe in the left, welded in two passes. The root presents small regions of corrosion in the weld metal and a localized corrosion at the fusion line of the 6063 pipe (knife-line attack morphology).
397
VIEW
ML00059 / Feb.2018
Intergranular Corrosion of Aluminum Piping
M - Aluminum ManganeseP - Welded JointAp - Chemical IndustryCd - Intergranular Corrosion
Cm - Keller Etched MacroDf - Localized Corrosion
Micrographic detail of a longitudinal section of the pipe AA 6063. Granular structure and dispersed particles.
138
VIEW
ML00059 / Feb.2018
Intergranular Corrosion of Aluminum Piping
M - Aluminum ManganeseP - Welded JointAp - Chemical IndustryCd - Intergranular Corrosion
Cm - Keller Etched MacroDf - Base Metal Right Side