Damage

2 cases · 18 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Standard: 5L clear all

Damage — sub-branches

Corrosion 1Cracking 1Leakage 3Localized Corrosion 6Microcracks 2Preferential Dissolution 5

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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
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

More from these cases

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
Aspect of the internal surface of the pipe after cutting, showing the colors of the internal deposits and the leaking line associated to the pipe seam.
290
VIEW
ML00140 / May.2019
Preferential Corrosion of Pipe Seam Weld
M - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Cm - Aspect Before AnalysisDf - Leakage
Detailed aspect of the internal surface of the pipe after cleaning, in a region where the pipe was leaking.
62
VIEW
ML00140 / May.2019
Preferential Corrosion of Pipe Seam Weld
M - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Cm - Aspect Before AnalysisDf - Leakage
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
Macrography of a transverse section of the pipe, 8 mm thick, presenting localized dissolution at the longitudinal autogenous seam weld.
65
VIEW
ML00140 / May.2019
Preferential Corrosion of Pipe Seam Weld
M - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Cm - NItal Etched MacroDf - Preferential Dissolution

+9 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
The HAZ presents microcracks at previous austenite grain boundaries. These regions melted during welding and generated cracks associated to low melting temperature phases.
48
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 - Microcracks
The HAZ presents microcracks at previous austenite grain boundaries. These regions melted during welding and generated cracks associated to low melting temperature phases.
43
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 - Microcracks