Damage

4 cases · 32 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Microstructure: Dendritic clear all

Damage — sub-branches

Casting defects 3Corrosion 4Cracking 2Cracks 3Fracture 4Leakage 5Localized Corrosion 7Secondary Cracks 2Thinning 2

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Aspect of a crevice corrosion of the flange, under the bolt head, showing evidences that the cathodic protection system was not connected to the stainless steel instrument.
1434
VIEW
ML00122 / Feb.2018
Crevice Corrosion in a Subsea System
M - Austenitic Stainless SteelP - CaseAp - Oil and GasCd - Crevice
Cm - Aspect Before AnalysisDf - Localized Corrosion
Micrography of a transverse section of the lifting part, showing interdendritic voids close to the surface at the inner diameter of the padeye. The microstructure is tempered martensite.
450
VIEW
ML00098 / Nov.2017
Brittle Fracture of a Casting Lifting Device
M - Low Alloy Medium Carbon QTP - CastingAp - LiftingCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Casting defects
Region of the leakage close to the welded joint between the pipe and the 90° elbow, in the 1 1/2" nominal diameter piping, SCH 40 (3.7 mm thick). See the schematic drawing in the next figure
966
VIEW
ML00065 / May.2017
Erosion Corrosion of Monel Piping
M - NiCu AlloyP - Seamless PipeAp - Chemical IndustryCd - Erosion Corrosion
Cm - Aspect Before AnalysisDf - Leakage
Aspect of the welded region after dye check showing several indications, later identified as hot cracks associated to the repair welding.
114
VIEW
ML00070 / Jan.2019
Automotive Light Alloy Wheel Repaired By Welding
M - Aluminum Silicon MagnesiumP - RimAp - AutomotiveCd - Removed From Service
Cm - Aspect by NDTDf - Cracks

More from these cases

ML00122 — Crevice Corrosion in a Subsea SystemM - Austenitic Stainless SteelP - CaseAp - Oil and GasCd - Crevice
Detail of the electronic device after removing the external case. It is corroded because seawater entered in the equipment that was pressurized from the external sea environment.
228
VIEW
ML00122 / Feb.2018
Crevice Corrosion in a Subsea System
M - Austenitic Stainless SteelP - CaseAp - Oil and GasCd - Crevice
Cm - Aspect Before AnalysisDf - 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
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
The case where the electronic device was installed suffered a localized corrosion that allowed the seawater to wet the internal side, destroying it. The position where the leakage occurred originally presented a hole that was sealed with a plug and the corrosion occurred in a crevice condition.
166
VIEW
ML00122 / Feb.2018
Crevice Corrosion in a Subsea System
M - Austenitic Stainless SteelP - CaseAp - Oil and GasCd - Crevice
Cm - Aspect Before AnalysisDf - Localized Corrosion

+5 more from this case →

ML00098 — Brittle Fracture of a Casting Lifting DeviceM - Low Alloy Medium Carbon QTP - CastingAp - LiftingCd - Brittle Fracture
Aspect of the fracture surface, showing a brittle morphology. Flat fracture with chevron marks from regions close to the internal diameter of the padeye, where there are secondary cracks.
22
VIEW
ML00098 / Nov.2017
Brittle Fracture of a Casting Lifting Device
M - Low Alloy Medium Carbon QTP - CastingAp - LiftingCd - Brittle Fracture
Cm - Aspect Before AnalysisDf - Fracture
Macrography of a "longitudinal" section of the padeye showing casting defects close to the internal diamater and a secondary crack, paralel to fracture, starting from the internal diameter. The fracture is not presented in this macro, it is to the top of the photo.
17
VIEW
ML00098 / Nov.2017
Brittle Fracture of a Casting Lifting Device
M - Low Alloy Medium Carbon QTP - CastingAp - LiftingCd - Brittle Fracture
Cm - NItal Etched MacroDf - Cracking
Macrographic detail of the secondary crack, paralel to fracture, starting from the internal diameter of the padeye. The dendritic structure is evident.
13
VIEW
ML00098 / Nov.2017
Brittle Fracture of a Casting Lifting Device
M - Low Alloy Medium Carbon QTP - CastingAp - LiftingCd - Brittle Fracture
Cm - NItal Etched MacroDf - Secondary Cracks
Micrography of the secondary crack, paralel to fracture, starting from the internal diameter of the padeye. The crack propagates in an interdendritic morphology, interconnecting casting defects.
13
VIEW
ML00098 / Nov.2017
Brittle Fracture of a Casting Lifting Device
M - Low Alloy Medium Carbon QTP - CastingAp - LiftingCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Secondary Cracks
Micrographic detail of the secondary crack, paralel to fracture, at the internal diameter of the padeye. The microstructure is martensitic.
14
VIEW
ML00098 / Nov.2017
Brittle Fracture of a Casting Lifting Device
M - Low Alloy Medium Carbon QTP - CastingAp - LiftingCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Cracking

+5 more from this case →

ML00065 — Erosion Corrosion of Monel PipingM - NiCu AlloyP - Seamless PipeAp - Chemical IndustryCd - Erosion Corrosion
Schematic drawing presenting the External piping surface
339
VIEW
ML00065 / May.2017
Erosion Corrosion of Monel Piping
M - NiCu AlloyP - Seamless PipeAp - Chemical IndustryCd - Erosion Corrosion
Cm - Identification drawingDf - Leakage
Aspect of the piping cut in the longitudinal direction, presenting the leakage region close to the welded joint between the pipe and the 90° elbow. The original SCH 40 (3.7 mm thickness) presents an actual average thickness of 2 mm all through the piping extension, evidencing a general thinning. See the schematic drawing in the next figure.
364
VIEW
ML00065 / May.2017
Erosion Corrosion of Monel Piping
M - NiCu AlloyP - Seamless PipeAp - Chemical IndustryCd - Erosion Corrosion
Cm - Aspect Before AnalysisDf - Leakage
Schematic drawing presenting the internal piping surface
234
VIEW
ML00065 / May.2017
Erosion Corrosion of Monel Piping
M - NiCu AlloyP - Seamless PipeAp - Chemical IndustryCd - Erosion Corrosion
Cm - Identification drawingDf - Leakage
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
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

+1 more from this case →

ML00070 — Automotive Light Alloy Wheel Repaired By WeldingM - Aluminum Silicon MagnesiumP - RimAp - AutomotiveCd - Removed From Service
Hot cracks in the fusion zone. The eutectic regions were melted and cracked in an interdendritic morphology.
37
VIEW
ML00070 / Jan.2019
Automotive Light Alloy Wheel Repaired By Welding
M - Aluminum Silicon MagnesiumP - RimAp - AutomotiveCd - Removed From Service
Cm - Micrography by SEMDf - Cracks
Detail of the hot cracks in the fusion zone. The eutectic regions were melted and cracked in an interdendritic morphology. Keller etch.
50
VIEW
ML00070 / Jan.2019
Automotive Light Alloy Wheel Repaired By Welding
M - Aluminum Silicon MagnesiumP - RimAp - AutomotiveCd - Removed From Service
Cm - Micrography by SEMDf - Cracks