Longitudinal Section

10 cases · 27 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Application: Subsea clear all

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Micrography of a longitudinal section, in the center, of the broken 5/8" bolt, presenting an aged martensitic structure. There are vertical "lines" that correspond to segregation bands due to the forming direction. These bands are evident only using low magnification microscopy.
168
VIEW
ML00139 / Jun.2018
Hydrogen Fracture of a 17-4 PH Allen Bolt
M - Precipitation Hardened Stainless SteelP - Allen BoltAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Longitudinal Section
Micrography of a longitudinal section of the forged bar in the center of the thickness. Ferrite and austenite. Coarse structure.
61
VIEW
ML00123 / Feb.2018
Non Qualified Superduplex for Subsea
M - Super Duplex Stainless SteelP - BarAp - Oil and GasCd - Not according to spec
Cm - NaOH Electrolytic Etched MicroDf - Longitudinal Section
Micrography of a longitudinal section in the center of the bolt. Granular austenitic microstructure, equiaxial, primary precipitates (isolated), precipitation hardened (not detectable by metalography, only because of the hardness level)
63
VIEW
ML00106 / Dec.2017
Inconel 718 Submarine Bolt
M - NiCrFe AlloyP - BoltAp - SubseaCd - Typical manufacturing
Cm - Kalling Etched Micrography by OMDf - Longitudinal Section
Low magnification micrography of the bolt in a longitudinal section, at the bolt thread, showing no evidences of forming operations, indicating it was machined from a heat treated bar. Austenitic microstructure, granular, equiaxial, precipitation hardened (shadow in the grains).
45
VIEW
ML00105 / Jun.2018
Inconel 718 Bolt of Special Head
M - NiCrFe AlloyP - FastenerAp - SubseaCd - Typical manufacturing
Cm - Kalling Etched Micrography by OMDf - Longitudinal Section
Macrography of a longitudinal section of the fitting to tubing weld, with the longitudinal cracking at the tubular fitting position.
69
VIEW
ML00094 / Sep.2017
MIC of a Subsea Hydraulic Line
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Behavior
Cm - Kalling Etched MacroDf - Longitudinal Section
Macrography of the longitudinal section of the tool joint, assembled. The pin is still attached to the box end of the other drill pipe in the column, showing that the pin fractured in the region of external diameter transition (right side of the figure), where the box was probably touching the pin shoulder. Interesting to note that the inner diameter still presents a sound coating.
73
VIEW
ML00088 / Dec.2017
Hydrogen Cracking of an API 5D S135 Drill Pipe
M - Low Alloy Medium Carbon QTP - Drill PipeAp - SubseaCd - Hydrogen Embrittlement
Cm - Longitudinal Section AspectDf - Longitudinal Section
Macrography of a longitudinal section of the broken bolt, at the fracture position, showing that the fracture is partially flat (left side), where the macroscopically aspect is brittle, and a final ductile fracture (right side). Interesting to note that there is a large longitudinal crack, secondary (transverse to the fracture surface).
143
VIEW
ML00074 / Jun.2018
Hydrogen Cracking of a 17-4 PH Subsea Bolt
M - Precipitation Hardened Stainless SteelP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched MacroDf - Longitudinal Section
Micrography of the longitudinal section of the forging material, presenting a granular austenite, precipitation hardened.
84
VIEW
ML00078 / Jun.2017
Hydrogen Cracking of IN 718 Subsea Connector
M - NiCrFe AlloyP - ForgingAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Longitudinal Section

More from these cases

ML00139 — Hydrogen Fracture of a 17-4 PH Allen BoltM - Precipitation Hardened Stainless SteelP - Allen BoltAp - SubseaCd - Hydrogen Embrittlement
Micrography of a longitudinal section of the 5/8" bolt, at the bottom of the thread, presenting a refined structure compared to the center of the bolt and a mark at the thread flank that was probably created during tightening of the bolt.
95
VIEW
ML00139 / Jun.2018
Hydrogen Fracture of a 17-4 PH Allen Bolt
M - Precipitation Hardened Stainless SteelP - Allen BoltAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Longitudinal Section
Micrography of a longitudinal section of the bolt, close to the fracture surface (top of the figure), The fracture started at the surface (left side) in a position close to the bolt body to bolt head transition.
58
VIEW
ML00139 / Jun.2018
Hydrogen Fracture of a 17-4 PH Allen Bolt
M - Precipitation Hardened Stainless SteelP - Allen BoltAp - SubseaCd - Hydrogen Embrittlement
Cm - As polished micrographyDf - Longitudinal Section
Macrography of the longidutinal section of a non broken allen bolt, at the threaded body to bolt head transition. The granular structure is different through the bolt, with refined structure in the threaded body and coarse at the transition.
44
VIEW
ML00139 / Jun.2018
Hydrogen Fracture of a 17-4 PH Allen Bolt
M - Precipitation Hardened Stainless SteelP - Allen BoltAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched MacroDf - Longitudinal Section
Micrography of a longitudinal section, in the center of a non-broken bolt that operated in the same assembling, presenting an aged martensitic structure, similar to the broken bolt.
41
VIEW
ML00139 / Jun.2018
Hydrogen Fracture of a 17-4 PH Allen Bolt
M - Precipitation Hardened Stainless SteelP - Allen BoltAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Longitudinal Section
Micrography of a longitudinal section of the non-broken 5/8" bolt, at the transition between the threaded body and the head, showing a variation in the grain size (of the previous austenite) and evidences of a deformed structure at this transition.
41
VIEW
ML00139 / Jun.2018
Hydrogen Fracture of a 17-4 PH Allen Bolt
M - Precipitation Hardened Stainless SteelP - Allen BoltAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Longitudinal Section
ML00123 — Non Qualified Superduplex for SubseaM - Super Duplex Stainless SteelP - BarAp - Oil and GasCd - Not according to spec
Micrography of a longitudinal section of the forged bar in the center of the thickness. Ferrite and austenite. The average austenite spacing is 80 microns, a lot larger than the maximum allowed in the specification, of 30 microns. No detrimental phases were identified at the ferrite/austenite interfaces, but the ferrite phase presented a rough aspect. Higher magnification analysis would be required to identify precipitation.
53
VIEW
ML00123 / Feb.2018
Non Qualified Superduplex for Subsea
M - Super Duplex Stainless SteelP - BarAp - Oil and GasCd - Not according to spec
Cm - NaOH Electrolytic Etched MicroDf - Longitudinal Section
ML00106 — Inconel 718 Submarine BoltM - NiCrFe AlloyP - BoltAp - SubseaCd - Typical manufacturing
Low magnification micrography of the bolt in a longitudinal section, at the bolt thread, showing no evidences of forming operations, indicating that it was machined from a heat treated bar. Austenitic microstructure, granular, equiaxial.
54
VIEW
ML00106 / Dec.2017
Inconel 718 Submarine Bolt
M - NiCrFe AlloyP - BoltAp - SubseaCd - Typical manufacturing
Cm - Kalling Etched Micrography by OMDf - Longitudinal Section
ML00105 — Inconel 718 Bolt of Special HeadM - NiCrFe AlloyP - FastenerAp - SubseaCd - Typical manufacturing
Low magnification micrography of the bolt in a longitudinal section, at the bolt head, showing no evidences of forming operations, indicating it was machined from a heat treated bar. Austenitic microstructure, granular, equiaxial, precipitation hardened (shadow in the grains).
31
VIEW
ML00105 / Jun.2018
Inconel 718 Bolt of Special Head
M - NiCrFe AlloyP - FastenerAp - SubseaCd - Typical manufacturing
Cm - Kalling Etched Micrography by OMDf - Longitudinal Section
Low magnification micrography of the bolt in a longitudinal section, in the center of the thickness. Austenitic microstructure, granular, equiaxial, precipitation hardened (shadow in the grains).
29
VIEW
ML00105 / Jun.2018
Inconel 718 Bolt of Special Head
M - NiCrFe AlloyP - FastenerAp - SubseaCd - Typical manufacturing
Cm - Kalling Etched Micrography by OMDf - Longitudinal Section
ML00094 — MIC of a Subsea Hydraulic LineM - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Behavior
Macrography of the fitting to tubing welded joint. The internal surface of the fitting (left side) is rough compared to the internal surface of the tubing (right side). The cracking is located only in the fitting and presented no association with the welded joint.
40
VIEW
ML00094 / Sep.2017
MIC of a Subsea Hydraulic Line
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Behavior
Cm - Kalling Etched MacroDf - Longitudinal Section
ML00074 — Hydrogen Cracking of a 17-4 PH Subsea BoltM - Precipitation Hardened Stainless SteelP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Micrography of the longitudinal section of the bolt, at the bottom of the thread fillet, showing that the fracture is intergranular in this position.
71
VIEW
ML00074 / Jun.2018
Hydrogen Cracking of a 17-4 PH Subsea Bolt
M - Precipitation Hardened Stainless SteelP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Longitudinal Section