Pipe

4 cases · 38 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Condition: Damage Standard: API Capture method: Optical Microscope clear all

Pipe — sub-branches

Longitudinal Seam Welded Pipe 2Seamless Pipe 2

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Micrography of the pipe transverse section presenting a granular microstructure.
147
VIEW
ML00140 / May.2019
Preferential Corrosion of Pipe Seam Weld
M - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Cm - Nital Etched Micrography by OMDf - Transverse Section
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
The microstructure of the pipe, presented in a longitudinal section, is an uniform tempered martensite.
105
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 Micrography by OMDf - Martensite
13Cr SS longitudinal section micrography, at the collapsed region, showing a ferritic matrix structure (overtempered) with the previous austenite grain boundaries decorated by phases (carbides and probably martensite islands), indicating that the material was exposed to a high tempering temperature that created a partial austenitizing condition. It explains the material low toughness and lower strenght (than required).
437
VIEW
ML00039 / Apr.2017
Collapse in Tubular 13Cr
M - Martensitic Stainless SteelP - Seamless PipeAp - Oil and GasCd - Heat Treatment Defect
Cm - Kalling Etched Micrography by OMDf - Longitudinal Section

More from these cases

ML00140 — Preferential Corrosion of Pipe Seam WeldM - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Micrography of the pipe transverse section presenting a predominatly ferritic-perlitic microstructure.
132
VIEW
ML00140 / May.2019
Preferential Corrosion of Pipe Seam Weld
M - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Cm - Nital Etched Micrography by OMDf - Ferrite and Pearlite
Micrographic detail of the predominatly ferritic-perlitic microstructure. Pipe transverse section.
95
VIEW
ML00140 / May.2019
Preferential Corrosion of Pipe Seam Weld
M - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Cm - Nital Etched Micrography by OMDf - Ferrite and Pearlite
Micrography of the pipe in the leakage area, showing the preferential corrosion in the center of the autogenous weld and oxides inside the crevice, that appearas as a cracking but that is only a localized anodic process.
66
VIEW
ML00140 / May.2019
Preferential Corrosion of Pipe Seam Weld
M - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Cm - Nital Etched Micrography by OMDf - Localized Corrosion
Micrographic detail of the autogenous seam weld. The localized dissolution occurrs exactly at the weld metal that presents a bainitic structure of average hardness about 230HV, compared to the heat affected zone presenting average of 202 HV and the base metal presenting average of 180HV.
57
VIEW
ML00140 / May.2019
Preferential Corrosion of Pipe Seam Weld
M - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Cm - Nital Etched Micrography by OMDf - Localized Corrosion
Micrographic detail presenting the slighltly decarburized ferritic structure, with inclusions, in the center of the weld, surrounded by a bainitic structure and the preferential corrosion in the weld.
51
VIEW
ML00140 / May.2019
Preferential Corrosion of Pipe Seam Weld
M - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Cm - Nital Etched Micrography by OMDf - Localized Corrosion

+5 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 liquation crack is a hot crack in the base metal (at the HAZ) that induces a solidification crack in the weld metal.
66
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 - Weld Metal
Micrographic detail of the cracks at the fusion line of the welded joint, at the connector side. The cracking presents morphology of melting regions of impurities at grain boundaries of the large grains of the heat affected zone (HAZ).
57
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 - Fusion Line
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
Micrography of the AISI 4130 forging, 5/8" thickness, close to the welded region, in the longitudinal section.
42
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 - Base Metal Left Side

+7 more from this case →

ML00068 — Corrosion Fatigue of a 5" Drill PipeM - Low Alloy Medium Carbon QTP - Seamless PipeAp - O&G Well DrillingCd - Corrosion Fatigue
The micrography in the as polished condition of the longitudinal section of the pipe close to the washout, shows that at the tool mark tip (notch from the external surface) a fatigue crack already started from a corroded region (pitting).
187
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 - Micrography by OMDf - Pitting
Micrographic detail, in the as polished condition, of the corrosion fatigue crack.
89
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 - Micrography by OMDf - Fatigue Crack
The micrography of one of the (multiple) cracks shows the slightly irregular morphology of the cracking, typical of a corrosion-fatigue mechanism.
281
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 Micrography by OMDf - Corrosion Cracking
Micrographic detail of the slightly irregular crack propagation, typical of a corrosion-fatigue mechanism.
76
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 Micrography by OMDf - Corrosion Cracking
ML00039 — Collapse in Tubular 13CrM - Martensitic Stainless SteelP - Seamless PipeAp - Oil and GasCd - Heat Treatment Defect
13Cr SS in the longitudinal section, at the collapsed region. Non uniform structure (ferritic matrix and decorated prior austenite grain boundaries) that evidences an usuitable heat treatment during fabrication, and explains the material low strenght.
54
VIEW
ML00039 / Apr.2017
Collapse in Tubular 13Cr
M - Martensitic Stainless SteelP - Seamless PipeAp - Oil and GasCd - Heat Treatment Defect
Cm - Kalling Etched Micrography by OMDf - Longitudinal Section
13Cr SS in the longitudinal section, at the collapsed region. Detail of the non uniform structure (ferritic matrix and decorated prior austenite grain boundaries) that evidences an usuitable heat treatment during fabrication, and explains the material low strenght.
48
VIEW
ML00039 / Apr.2017
Collapse in Tubular 13Cr
M - Martensitic Stainless SteelP - Seamless PipeAp - Oil and GasCd - Heat Treatment Defect
Cm - Kalling Etched Micrography by OMDf - Prior Austenite Boundaries Decorated
13Cr SS in the transverse section, at the collapsed region, showing a non uniform structure that evidences an usuitable heat treatment during fabrication, and explains the material low strenght.
29
VIEW
ML00039 / Apr.2017
Collapse in Tubular 13Cr
M - Martensitic Stainless SteelP - Seamless PipeAp - Oil and GasCd - Heat Treatment Defect
Cm - Kalling Etched Micrography by OMDf - Transverse Section
13Cr SS transverse section micrography, at the collapsed region, showing a ferritic matrix structure (overtempered) with the previous austenite grain boundaries decorated by phases (carbides and probably martensite islands), indicating that the material was exposed to a high tempering temperature that created a partial austenitizing condition. It explains the material low toughness and lower strenght (than required).
29
VIEW
ML00039 / Apr.2017
Collapse in Tubular 13Cr
M - Martensitic Stainless SteelP - Seamless PipeAp - Oil and GasCd - Heat Treatment Defect
Cm - Kalling Etched Micrography by OMDf - Transverse Section
The micrography of the 13Cr SS in the transverse section, at the collapsed region, shows a ferritic matrix structure (overtempered) with the previous austenite grain boundaries decorated by phases (carbides and probably martensite islands), indicating that the material was exposed to a high tempering temperature that created a partial austenitizing condition. It explains the material low toughness and lower strenght (than required).
32
VIEW
ML00039 / Apr.2017
Collapse in Tubular 13Cr
M - Martensitic Stainless SteelP - Seamless PipeAp - Oil and GasCd - Heat Treatment Defect
Cm - Kalling Etched Micrography by OMDf - Overtempered Structure

+3 more from this case →