Naked Eye or Stereoscope

4 cases · 8 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Product: Fastener clear all

Naked Eye or Stereoscope — sub-branches

Fracture Surface Aspect 2Kalling Etched Macro 1Longitudinal Section Aspect 2NItal Etched Macro 3

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Macrography of a stud longitudinal sectiion at the fracture position (top of the figure). It is possible to see a large secondary crack at the bottom of the thread fillet adjacent to the fracture surface, without any deformation evidence. This reveals a brittle material behavior, although the hardness measured at the stud end revealed 33HRc, as should be expected by the material specification.
56
VIEW
ML00136 / Jun.2018
Hydrogen Cracks of Subsea Studs
M - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - NItal Etched MacroDf - Secondary Cracks
Macrography of a longitudinal section of the eye bolt, presenting the fracture in the top of the figure and the threads in the left side of the figure. Details of the fracture of the first thread fillet below the fracture are presented in the next figures.
225
VIEW
ML00120 / Jun.2018
Ductile Rupture of a Carbon Steel Eye Bolt
M - Low Carbon SteelP - FastenerAp - AutomotiveCd - Overload
Cm - NItal Etched MacroDf - Longitudinal Section
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
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

More from these cases

ML00120 — Ductile Rupture of a Carbon Steel Eye BoltM - Low Carbon SteelP - FastenerAp - AutomotiveCd - Overload
Micrography as polished of the longitudinal section of the bolt at the first thread fillet below the fracture, presenting a cracking at the bottom of the fillet.
194
VIEW
ML00120 / Jun.2018
Ductile Rupture of a Carbon Steel Eye Bolt
M - Low Carbon SteelP - FastenerAp - AutomotiveCd - Overload
Cm - NItal Etched MacroDf - Crack
ML00074 — Hydrogen Cracking of a 17-4 PH Subsea BoltM - Precipitation Hardened Stainless SteelP - FastenerAp - SubseaCd - Hydrogen Embrittlement
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
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
ML00077 — Hydrogen Cracking of LAS Subsea BoltsM - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
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