Atlas

2 cases · 54 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

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
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
Nitronic 60 cylinder. Scanning electron microscopy image of a corroded region at the external surface of the cylinder, that is austenitic.  The image shows the localized corroded regions in form of pits.
1228
ML00121 / Feb.2018
Pitting Corrosion in a Subsea System
M - Austenitic / MartensiticP - Rod & CylinderAp - SubseaCd - Pitting Corrosion
Cm - Surface Aspect by SEMDf - Localized Corrosion

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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
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.
133
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
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
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
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 →

ML00121 — Pitting Corrosion in a Subsea SystemM - Austenitic / MartensiticP - Rod & CylinderAp - SubseaCd - Pitting Corrosion
Aspect of the Nitronic 60 cylinder, OD 36.4mm, presenting pits at the external surface.
219
ML00121 / Feb.2018
Pitting Corrosion in a Subsea System
M - Austenitic / MartensiticP - Rod & CylinderAp - SubseaCd - Pitting Corrosion
Cm - Aspect Before AnalysisDf - External Surface
Nitronic 60 cylinder. Detailed aspect of the pitting in a low magnification microscope.
197
ML00121 / Feb.2018
Pitting Corrosion in a Subsea System
M - Austenitic / MartensiticP - Rod & CylinderAp - SubseaCd - Pitting Corrosion
Cm - Surface AspectDf - Pitting
Nitronic 60 cylinder. Micrography of the longitudinal section in the center of the thickness, presenting a fully austenitic microstructure, equiaxial grains, and evidences of the manufacturing process by hot forming.
179
ML00121 / Feb.2018
Pitting Corrosion in a Subsea System
M - Austenitic / MartensiticP - Rod & CylinderAp - SubseaCd - Pitting Corrosion
Cm - Micrography by OM using A262 Method ADf - Austenite
Nitronic 60 cylinder. Micrography of the longitudinal section in the center of the thickness, presenting a fully austenitic microstructure, with some aligned non metallic inclusions.
157
ML00121 / Feb.2018
Pitting Corrosion in a Subsea System
M - Austenitic / MartensiticP - Rod & CylinderAp - SubseaCd - Pitting Corrosion
Cm - Micrography by OM using A262 Method ADf - Austenite
Nitronic 60 cylinder. Micrographic detail of the longitudinal section in the center of the thickness, presenting a fully austenitic microstructure, equiaxial grains, typical of a solution annealed condition.
136
ML00121 / Feb.2018
Pitting Corrosion in a Subsea System
M - Austenitic / MartensiticP - Rod & CylinderAp - SubseaCd - Pitting Corrosion
Cm - Micrography by OM using A262 Method ADf - Austenite

+14 more from this case →