Hydrogen

11 cases · 178 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Application: Subsea clear all

Hydrogen — sub-branches

Hydrogen Embrittlement 11

Results

SortNewestOldestTitle A-ZTitle Z-A
General aspect of the 5/8" allen bolt that was found fractured in an instrument connected to a subsea BOP. The fracture presented a brittle aspect and occurred at the bolt head to threaded body transition.
1495
VIEW
ML00139 / Jun.2018
Hydrogen Fracture of a 17-4 PH Allen Bolt
M - Precipitation Hardened Stainless SteelP - Allen BoltAp - SubseaCd - Hydrogen Embrittlement
Cm - Aspect Before AnalysisDf - Fracture
Aspect of the broken stud that was fastening a flanged line in a subsea body (tapped hole) using a nut. The fracture, transverse to the stud axis, occurred exactly at the body to flange interface. Adjacent to the fracture, all thread fillets (positioned inside the flange hole) presented cracks at the bottom of the thread. The stud was operating during seven years and was not corroded, indicating it was protected by the anodes. There are also deposits in the fillets suggesting the cathodic protection was effective even inside the flange hole.
799
VIEW
ML00136 / Jun.2018
Hydrogen Cracks of Subsea Studs
M - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Aspect Before AnalysisDf - General View
Aspect of the fracture surface of the bolt, after cleaning with a plastic brush. Although there is a layer of oxides it is possible to see the intergranular morphology of the fracture, typical of a hydrogen embrittlement mechanism.
1154
VIEW
ML00126 / Mar.2018
Hydrogen Fracture of Subsea Allen Bolts
M - Low Alloy Medium Carbon QTP - Coated ProductAp - SubseaCd - Hydrogen Embrittlement
Cm - Fractography by SEMDf - Intergranular Fracture
Micrographic detail of a longitudinal section of the pin, at the fracture position, showing secondary cracks with intergranular and transgranular morphology.
59
VIEW
ML00009 / Sep.2017
Hydrogen Cracking of a 5" Drill Pipe S135
M - Low Alloy Medium Carbon QTP - Drill PipeAp - SubseaCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Brittle Cracks
Aspect of the fracture surface of the pin, still assembled in the box (that is externally to the pin). The pin fracture is flat, presenting radial marks.
791
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 - Aspect Before AnalysisDf - Brittle Fracture
Aspect of the broken bolt 1 1/2" nominal diameter, after a short time in service (non residente subsea equipment) under cathodic protection. The bolt broke at the thread fillet, close to the head.
800
VIEW
ML00074 / Jun.2018
Hydrogen Cracking of a 17-4 PH Subsea Bolt
M - Precipitation Hardened Stainless SteelP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Aspect Before AnalysisDf - General View
Detail of the fracture surface, predominantly transgranular with secondary cracks of intergranular morphology.
831
VIEW
ML00078 / Jun.2017
Hydrogen Cracking of IN 718 Subsea Connector
M - NiCrFe AlloyP - ForgingAp - SubseaCd - Hydrogen Embrittlement
Cm - Fractography by SEMDf - Brittle Fracture
Micrography of a longitudinal section of the bolt, as polished, presenting brittle cracks, transverse to the bolt axis.
1241
VIEW
ML00077 / Jun.2018
Hydrogen Cracking of LAS Subsea Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Micrography by OMDf - Cracks

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, 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, in the center, of the broken 5/8" bolt, presenting an aged martensitic structure.
132
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 - Martensite
Micrographic detail of the aged martensitic structure. The bolt presented variations in the previous austenite grain boundaries from the center of the thickness to the surface. No delta ferrite or retained austenite islands are evidenced.
107
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 - Martensite
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 5/8" bolt, at the bottom of the thread, presenting a refined structure compared to the center of the bolt. The structure is aged martensite.
91
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 - Martensite

+28 more from this case →

ML00136 — Hydrogen Cracks of Subsea StudsM - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Longitudinal section micrography in a position of the thread, far from the failure. The stud presented a quenching and tempering structure and the thread was machined.
84
VIEW
ML00136 / Jun.2018
Hydrogen Cracks of Subsea Studs
M - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Machined Thread
Microstructure of the stud in the longitudinal section, presenting segregated bands, not uniformly distributed in the section. The bands are associated to elongated and aligned inclusions, and a refined microstructure, probably due to carbon and alloying elements concentration.
69
VIEW
ML00136 / Jun.2018
Hydrogen Cracks of Subsea Studs
M - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Banded Structure
Microstructure of the stud in the longitudinal section, out of a region of segregation, where the tempered martensitic microstructure appears more uniform.
72
VIEW
ML00136 / Jun.2018
Hydrogen Cracks of Subsea Studs
M - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Martensite
Micrographic detail of the segregated bands, not uniformly distributed in the section. The bands are associated to elongated and aligned inclusions, and a refined microstructure, probably due to carbon and alloying elements concentration. The localized microhardness (50g) in the band showed levels about 540HV, and out of the band, in the same localtion, presented an average hardness of 321 HV, indicating that the material is non uniform in the regions where there are bands.
66
VIEW
ML00136 / Jun.2018
Hydrogen Cracks of Subsea Studs
M - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Banded Structure
Micrographic detail of the martensitic structure of the stud in the longitudinal section, out of a region of segregation, where the microstructure appears more uniform and the microhardness is about 370HV (50g).
62
VIEW
ML00136 / Jun.2018
Hydrogen Cracks of Subsea Studs
M - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Martensite

+24 more from this case →

ML00126 — Hydrogen Fracture of Subsea Allen BoltsM - Low Alloy Medium Carbon QTP - Coated ProductAp - SubseaCd - Hydrogen Embrittlement
Detailed aspect of the fracture surface of the bolt, evidencing the intergranular morphology of the fracture (although with an oxide scale), typical of a hydrogen embrittlement mechanism.
114
VIEW
ML00126 / Mar.2018
Hydrogen Fracture of Subsea Allen Bolts
M - Low Alloy Medium Carbon QTP - Coated ProductAp - SubseaCd - Hydrogen Embrittlement
Cm - Fractography by SEMDf - Intergranular Fracture
Aspect of the broken bolt, 5/8" Allen, socket head cap screw, originally 1 3/4" long, broken in subsea service under cathodic protection. The bolt presents a zinc coating.
116
VIEW
ML00126 / Mar.2018
Hydrogen Fracture of Subsea Allen Bolts
M - Low Alloy Medium Carbon QTP - Coated ProductAp - SubseaCd - Hydrogen Embrittlement
Cm - Aspect Before AnalysisDf - General View
Micrography of the longitudinal section of the bolt showing a martensitic structure, with segregation bands evidenced by the chemical etch.
99
VIEW
ML00126 / Mar.2018
Hydrogen Fracture of Subsea Allen Bolts
M - Low Alloy Medium Carbon QTP - Coated ProductAp - SubseaCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Banded Structure
Micrography of the longitudinal section of the bolt at the bottom of the thread fillet, showing the uniform martensitic structure, not strain hardened.
90
VIEW
ML00126 / Mar.2018
Hydrogen Fracture of Subsea Allen Bolts
M - Low Alloy Medium Carbon QTP - Coated ProductAp - SubseaCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Uniform Structure
Micrography of the longitudinal section of the bolt at the top of the thread fillet, showing a small circunferential cracking typically of a rolling process to manufacture the thread. The thread presented no evidences of plastic deformation suggesting that the heat treatment was applied later. It is important to mention that this cracking presented no influence in the fracture of the bolt.
101
VIEW
ML00126 / Mar.2018
Hydrogen Fracture of Subsea Allen Bolts
M - Low Alloy Medium Carbon QTP - Coated ProductAp - SubseaCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Rolled Thread

+9 more from this case →

ML00009 — Hydrogen Cracking of a 5" Drill Pipe S135M - Low Alloy Medium Carbon QTP - Drill PipeAp - SubseaCd - Hydrogen Embrittlement
Aspect of the fracture that occurred in the connection between the pin of one DP and the box of other DP, in the pin side. The photo presents the pin still connected in the box. The flat fracture indicates a brittle behavior.
641
VIEW
ML00009 / Sep.2017
Hydrogen Cracking of a 5" Drill Pipe S135
M - Low Alloy Medium Carbon QTP - Drill PipeAp - SubseaCd - Hydrogen Embrittlement
Cm - Aspect Before AnalysisDf - General View
Aspect of the broken pin after removal from the box end.
125
VIEW
ML00009 / Sep.2017
Hydrogen Cracking of a 5" Drill Pipe S135
M - Low Alloy Medium Carbon QTP - Drill PipeAp - SubseaCd - Hydrogen Embrittlement
Cm - Aspect Before AnalysisDf - Brittle Fracture
Detail of the fracture surface with a starting point at the external surface of the pin.
91
VIEW
ML00009 / Sep.2017
Hydrogen Cracking of a 5" Drill Pipe S135
M - Low Alloy Medium Carbon QTP - Drill PipeAp - SubseaCd - Hydrogen Embrittlement
Cm - Aspect Before AnalysisDf - Brittle Fracture
Macroscopic detail of the fracture surface with a starting point at the external surface of the pin.
82
VIEW
ML00009 / Sep.2017
Hydrogen Cracking of a 5" Drill Pipe S135
M - Low Alloy Medium Carbon QTP - Drill PipeAp - SubseaCd - Hydrogen Embrittlement
Cm - Fracture Surface AspectDf - Brittle Fracture
The fractography by SEM shows intergranular fracture close to the external surface of the pin.
93
VIEW
ML00009 / Sep.2017
Hydrogen Cracking of a 5" Drill Pipe S135
M - Low Alloy Medium Carbon QTP - Drill PipeAp - SubseaCd - Hydrogen Embrittlement
Cm - Fractography by SEMDf - Intergranular Cracking

+9 more from this case →

ML00088 — Hydrogen Cracking of an API 5D S135 Drill PipeM - Low Alloy Medium Carbon QTP - Drill PipeAp - SubseaCd - Hydrogen Embrittlement
Micrographic detail of the quenched and tempered martensitic structure of the pin tool joint.
83
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 - Nital Etched Micrography by OMDf - Martensite
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
Visual aspect of the tool joint (TJ) that fractured in the pin body when it was assembled (the box appears as a sleeve in the pin OD). The internal coating is not damaged. The fracture is flat and presents little evidences of plastic deformation, indicating that the pin broke in a brittle way.
69
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 - Aspect by NDTDf - Brittle Fracture
Detail of the flat fracture surface of the pin, after disassembling from the TJ box. ID in the top and OD in the bottom of the figure. Radial marks are clear in the fracture surface.
57
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 - Fracture Surface AspectDf - Brittle Fracture
Fractographic analysis of the pin fracture surface showing inter and transgranular morphologies of fracture micromechanisms.
53
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 - Fractography by SEMDf - Brittle Fracture

+6 more from this case →

ML00074 — Hydrogen Cracking of a 17-4 PH Subsea BoltM - Precipitation Hardened Stainless SteelP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Fracture view presenting two diferente aspects, brittle in the bottom of the figure and in the center (most part of the fracture) and ductile in the top of the figure. Nominal diameter of the bolt 1 1/2".
203
VIEW
ML00074 / Jun.2018
Hydrogen Cracking of a 17-4 PH Subsea Bolt
M - Precipitation Hardened Stainless SteelP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Fracture Surface AspectDf - General View
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
Fractographic aspect of the broken fastener, at the surface, showing na intergranular morphology typical of a hydrogen assisted mechanism of a high strenght steel under cathodic protection.
224
VIEW
ML00074 / Jun.2018
Hydrogen Cracking of a 17-4 PH Subsea Bolt
M - Precipitation Hardened Stainless SteelP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Fractography by SEMDf - Intergranular Cracking
Detail of the brittle part of the bolt fracture, presenting a secondary cracking longitudinal to the bolt axis. The region of the bolt at the bottom of the thread (close to the surface) is brighter than the internal part of the bolt suggesting different fracture mechanisms.
111
VIEW
ML00074 / Jun.2018
Hydrogen Cracking of a 17-4 PH Subsea Bolt
M - Precipitation Hardened Stainless SteelP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Fracture Surface AspectDf - Fracture
Microscopic aspect of the fracture, close to the bolt surface where the fracture is macroscopically brittle, presenting a predominantly intergranular fracture micromechanism.
108
VIEW
ML00074 / Jun.2018
Hydrogen Cracking of a 17-4 PH Subsea Bolt
M - Precipitation Hardened Stainless SteelP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Fractography by SEMDf - Brittle Fracture

+8 more from this case →

ML00078 — Hydrogen Cracking of IN 718 Subsea ConnectorM - NiCrFe AlloyP - ForgingAp - SubseaCd - Hydrogen Embrittlement
Brittle aspect of the failure of the conector in the male thread. Both sides of the fracture.
96
VIEW
ML00078 / Jun.2017
Hydrogen Cracking of IN 718 Subsea Connector
M - NiCrFe AlloyP - ForgingAp - SubseaCd - Hydrogen Embrittlement
Cm - Aspect Before AnalysisDf - General View
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
Fractography by SEM, showing intergranular and transgranular fracture micromechanisms.
72
VIEW
ML00078 / Jun.2017
Hydrogen Cracking of IN 718 Subsea Connector
M - NiCrFe AlloyP - ForgingAp - SubseaCd - Hydrogen Embrittlement
Cm - Fractography by SEMDf - Brittle Fracture
Micrography of the longitudinal section of the conector, at the fracture position, showing secondary cracks from the fracture surface.
63
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
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

+3 more from this case →

ML00077 — Hydrogen Cracking of LAS Subsea BoltsM - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Aspect of the bolt fracture. The fracture appearance is irregular and there are several secondary cracks from thread fillets.
245
VIEW
ML00077 / Jun.2018
Hydrogen Cracking of LAS Subsea Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Aspect Before AnalysisDf - General View
Aspect of the bolt surface with a detail of a secondary crack at the first thread fillet, close to the bolt head.
147
VIEW
ML00077 / Jun.2018
Hydrogen Cracking of LAS Subsea Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Aspect Before AnalysisDf - Secondary Cracks
Aspect of the bolt fracture. The fracture appearance is irregular.
137
VIEW
ML00077 / Jun.2018
Hydrogen Cracking of LAS Subsea Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Aspect Before AnalysisDf - Fracture
The longitudinal macrosection shows the fracture appearance, irregular, and a lot of secondary cracks transverse to the bolt axis, and longitudinal.
126
VIEW
ML00077 / Jun.2018
Hydrogen Cracking of LAS Subsea Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Longitudinal Section AspectDf - Longitudinal Section
Several secondary cracks in the broken bolt, responsible for the irregular shape of the fracture, that presentes brittle cracks in the transverse and longitudinal directions.
109
VIEW
ML00077 / Jun.2018
Hydrogen Cracking of LAS Subsea Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Longitudinal Section AspectDf - Longitudinal Section

+10 more from this case →