Atlas

6 cases · 25 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Product: Forging Capture method: Optical Microscope Detail focus: Damage clear all

Results

SortNewestOldestTitle A-ZTitle Z-A
Micrography of the thread at the valve body surface, showing localized dissolution of the thread.
73
VIEW
ML00184 / Apr.2023
Dissimilar Steels in a Threaded Connection
M - Low Carbon SteelP - ForgingAp - OffshoreCd - Localized Dissolution
Cm - Nital Etched Micrography by OMDf - Corroded Thread
Low magnification micrographic aspect of the cracking. It is brittle, transgranular and associated to the ferritic/sigma phase interfaces.
54
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 MicroDf - Brittle Cracks
Micrography of a transverse section of the ring, at the pitting position, as polished, showing that there are intergranular cracks and the martensitic structure is corroded (chemical dissolution) inside the pitting.
33
VIEW
ML00124 / Feb.2018
MIC of a Martensitic Valve Ring
M - Martensitic Stainless SteelP - ForgingAp - EnergyCd - Brittle Behavior
Cm - As polished micrographyDf - Corrosion
Micrography of the longitudinal section of the conector, at the fracture position, showing secondary cracks from the fracture surface.
64
VIEW
ML00078 / Jun.2017
Hydrogen Cracking of IN 718 Subsea Connector
M - NiCrFe AlloyP - ForgingAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Fracture
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
Macrography transverse to the circunferential weld, longitudinal to the piping, presenting the location, a little far from the welded joint margin, where the through wall cracking is positioned.
160
VIEW
ML00002 / Jan.2018
Preferential Dissolution and Cracks in SDSS
M - Super Duplex Stainless SteelP - Fabrication WeldAp - PipingCd - Preferential Dissolution
Cm - NaOH Electrolytic Etched MicroDf - Through Wall Cracking

More from these cases

ML00184 — Dissimilar Steels in a Threaded ConnectionM - Low Carbon SteelP - ForgingAp - OffshoreCd - Localized Dissolution
Micrography of the valve body carbon steel thread, in the peak. Ferritic-bainitic structure.
64
VIEW
ML00184 / Apr.2023
Dissimilar Steels in a Threaded Connection
M - Low Carbon SteelP - ForgingAp - OffshoreCd - Localized Dissolution
Cm - Nital Etched Micrography by OMDf - Corroded Thread
Micrographic detail of the valve body carbon steel thread, in the peak. Ferritic-bainitic structure.
55
VIEW
ML00184 / Apr.2023
Dissimilar Steels in a Threaded Connection
M - Low Carbon SteelP - ForgingAp - OffshoreCd - Localized Dissolution
Cm - Nital Etched Micrography by OMDf - Corroded Thread
Cross-section near a threaded surface showing an acicular matrix structure bordered by a dark, layered corrosion/oxide band along the thread root.
1
VIEW
ML00184 / Apr.2023
Dissimilar Steels in a Threaded Connection
M - Low Carbon SteelP - ForgingAp - OffshoreCd - Localized Dissolution
Cm - Nital Etched Micrography by OMDf - Oxide Layer
ML00134 — Brittle Fracture of a Superduplex Valve BodyM - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Fracture
Micrographic details of the cracking. It is brittle, transgranular and associated to the ferritic/sigma phase interfaces.
50
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 MicroDf - Brittle Cracks
Micrographic aspect of the cracking. It is brittle, transgranular and associated to the ferritic/sigma phase interfaces.
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 MicroDf - Brittle Cracks
ML00124 — MIC of a Martensitic Valve RingM - Martensitic Stainless SteelP - ForgingAp - EnergyCd - Brittle Behavior
Micrographic detail of a transverse section of the ring, showing the corroded martensitic structure (chemical dissolution) inside the pitting.
32
VIEW
ML00124 / Feb.2018
MIC of a Martensitic Valve Ring
M - Martensitic Stainless SteelP - ForgingAp - EnergyCd - Brittle Behavior
Cm - As polished micrographyDf - Corrosion
Micrographic detail of a transverse section of the ring, showing the corroded martensitic structure (chemical dissolution) inside the pitting.
33
VIEW
ML00124 / Feb.2018
MIC of a Martensitic Valve Ring
M - Martensitic Stainless SteelP - ForgingAp - EnergyCd - Brittle Behavior
Cm - As polished micrographyDf - Intergranular Cracking
Micrography of a transverse section of the ring at the cracking position. The cracks are intergranular and opened at the position close to the surface. it is possible to identify dissolution of the structure adjacent to the grain boundaries,
25
VIEW
ML00124 / Feb.2018
MIC of a Martensitic Valve Ring
M - Martensitic Stainless SteelP - ForgingAp - EnergyCd - Brittle Behavior
Cm - Kalling Etched Micrography by OMDf - Crack
Micrographic detail of a transverse section of the ring at the cracking position. The cracks are intergranular and opened at the position close to the surface. it is possible to identify dissolution of the structure adjacent to the grain boundaries,
24
VIEW
ML00124 / Feb.2018
MIC of a Martensitic Valve Ring
M - Martensitic Stainless SteelP - ForgingAp - EnergyCd - Brittle Behavior
Cm - Kalling Etched Micrography by OMDf - Intergranular Cracking
Micrograph showing a fine acicular martensitic matrix with a branching crack network, more extensive near the right edge.
25
VIEW
ML00124 / Feb.2018
MIC of a Martensitic Valve Ring
M - Martensitic Stainless SteelP - ForgingAp - EnergyCd - Brittle Behavior
Cm - Kalling Etched Micrography by OMDf - Crack

+2 more from this case →

ML00078 — Hydrogen Cracking of IN 718 Subsea ConnectorM - NiCrFe AlloyP - ForgingAp - SubseaCd - Hydrogen Embrittlement
The micrographic detail of the longitudinal section at the fracture surface shows intergranular morphology for the secondary cracks (longitudinal to the forging axis).
64
VIEW
ML00078 / Jun.2017
Hydrogen Cracking of IN 718 Subsea Connector
M - NiCrFe AlloyP - ForgingAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Secondary Cracks
Micrographic detail of a longitudinal section of the connector, at the fracture surface (in the top), showing intergranular secondary cracks.
54
VIEW
ML00078 / Jun.2017
Hydrogen Cracking of IN 718 Subsea Connector
M - NiCrFe AlloyP - ForgingAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Intergranular Cracking
Micrographic detail of a longitudinal section of the connector, at the fracture surface (in the top), showing intergranular secondary cracks. There is a large amount of delta phase precipitated intergranular and intragranluar.
48
VIEW
ML00078 / Jun.2017
Hydrogen Cracking of IN 718 Subsea Connector
M - NiCrFe AlloyP - ForgingAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Secondary Cracks
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
ML00002 — Preferential Dissolution and Cracks in SDSSM - Super Duplex Stainless SteelP - Fabrication WeldAp - PipingCd - Preferential Dissolution
Longitudinal section micrography at the cracked position, close to the external surface of the flange, showing cracks transverse to the thickness, associated to the microstructure.
147
VIEW
ML00002 / Jan.2018
Preferential Dissolution and Cracks in SDSS
M - Super Duplex Stainless SteelP - Fabrication WeldAp - PipingCd - Preferential Dissolution
Cm - NaOH Electrolytic Etched MicroDf - Cracks Transverse to the Surface
Longitudinal section micrography at the cracked position, close to the internal surface of the flange (exposed to the corrosive fluid), showing preferential dissolution associated to the microstructure.
133
VIEW
ML00002 / Jan.2018
Preferential Dissolution and Cracks in SDSS
M - Super Duplex Stainless SteelP - Fabrication WeldAp - PipingCd - Preferential Dissolution
Cm - NaOH Electrolytic Etched MicroDf - Preferential Dissolution