Hydrogen

2 cases · 9 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Microstructure: Coating Layer Capture method: Optical Microscope Detail focus: Damage clear all

Hydrogen — sub-branches

Hydrogen Embrittlement 2

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Micrography of the longitudinal section of the stud showing internal cracks, secondary (not the cracks that opened the fracture). It is evident that the cracking from the thread fillet, of a ductile aspect, presented a different aspect than the internal cracks, of a brittle aspect.
31
VIEW
ML00127 / May.2018
Hydrogen Cracks of Cadmium Plated Studs
M - Low Alloy Medium Carbon QTP - Allen StudAp - Oil and GasCd - Hydrogen Embrittlement
Cm - As polished micrographyDf - Cracks
Micrography of the longitudinal section of the bolt, at the fracture (top of the figure), starting from the bottom of the thread (to the left side of the figure). The presence of the coating at the bolt surface shows that the fracture occurred without corrosion. The rusted aspect of the fracture is associated to corrosion products after the rupture has occurred, also suggesting that the bolts were fractured and remained in service for some time after the failure occurred.
65
VIEW
ML00126 / Mar.2018
Hydrogen Fracture of Subsea Allen Bolts
M - Low Alloy Medium Carbon QTP - Coated ProductAp - SubseaCd - Hydrogen Embrittlement
Cm - As polished micrographyDf - Fracture

More from these cases

ML00127 — Hydrogen Cracks of Cadmium Plated StudsM - Low Alloy Medium Carbon QTP - Allen StudAp - Oil and GasCd - Hydrogen Embrittlement
Micrography of the longitudinal section of the stud showing a crack from the thread fillet, of a ductile aspect, opened during torque.
30
VIEW
ML00127 / May.2018
Hydrogen Cracks of Cadmium Plated Studs
M - Low Alloy Medium Carbon QTP - Allen StudAp - Oil and GasCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Fracture
Micrography of the longitudinal section of the stud at the fracture (top of the figure) of a brittle aspect.
29
VIEW
ML00127 / May.2018
Hydrogen Cracks of Cadmium Plated Studs
M - Low Alloy Medium Carbon QTP - Allen StudAp - Oil and GasCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Fracture
Micrography of the longitudinal section of the stud at the fracture (top of the figure) of a brittle intergranular aspect.
25
VIEW
ML00127 / May.2018
Hydrogen Cracks of Cadmium Plated Studs
M - Low Alloy Medium Carbon QTP - Allen StudAp - Oil and GasCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Intergranular Fracture
Micrography of the longitudinal section of the stud at the fracture (top of the figure) of a brittle intergranular aspect.
24
VIEW
ML00127 / May.2018
Hydrogen Cracks of Cadmium Plated Studs
M - Low Alloy Medium Carbon QTP - Allen StudAp - Oil and GasCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Intergranular Cracking
ML00126 — Hydrogen Fracture of Subsea Allen BoltsM - Low Alloy Medium Carbon QTP - Coated ProductAp - SubseaCd - Hydrogen Embrittlement
Micrography, after NItal etching, of the longitudinal section of the bolt, at the fracture (top of the figure), starting from the bottom of the thread (to the left side of the figure). The presence of the coating at the bolt surface shows that the fracture occurred without corrosion.
56
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 - Fracture
Micrography of the longitudinal section of the bolt, in the center of the thickness, showing at the fracture surface (top of the figure), secondary cracks that are perpendicular to the fracture, associated to segregation bands.
55
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 - Secondary Cracks
Micrographic detail of the longitudinal section of the bolt, in the center of the thickness, showing the secondary cracks associated to segregation bands.
63
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 - Secondary Cracks