Optical Microscope

20 cases · 192 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Longitudinal section of the main pipe showing as austenitic structure with small amount of delta ferrite, aligned. The white band in the center of the figure is a segregation band that was not fully etched.
133
ML00006 / Apr.2017
Vibration Induced Fatigue in 304SS
M - Austenitic Stainless SteelP - Longitudinal Seam Welded PipeAp - PipingCd - Vibration Induced Fatigue
Cm - Micrography by OM using A262 Method ADf - Austenite
The micrography of a longitudinal section of the pipe, close to the internal surface, shows a general corrosion mechanism (with slow wall thickness loss), although the graphite/matrix interface is corroded preferentially.
569
ML00034 / Apr.2017
45 Years Old Acquaduct Grey Cast Iron
M - Gray Cast ironP - Centrifugally Cast PipeAp - AcquaductCd - General Corrosion
Cm - Nital Etched Micrography by OMDf - Corrosion
The microstructure of the pipe base metal, in the center of the thickness, is granular alpha.
102
ML00005 / Apr.2017
Environmental Hydrogen Damage in Ti Pipe
M - Unalloyed TitaniumP - Longitudinal Seam Welded PipeAp - PipingCd - Hydride Formation
Cm - Kroll Etched Micrography by OMDf - Granular structure
Micrography of a transverse section of the pipe, presenting the pitting corrosion. As polished.
310
ML00014 / Apr.2017
Pitting Corrosion in 316SS Pipe
M - Austenitic Stainless SteelP - Seamless PipeAp - FPSOCd - Pitting Corrosion
Cm - Micrography by OMDf - Pitting

More from these cases

ML00006 — Vibration Induced Fatigue in 304SSM - Austenitic Stainless SteelP - Longitudinal Seam Welded PipeAp - PipingCd - Vibration Induced Fatigue
Longitudinal section of the main pipe showing as austenitic structure with small amount of delta ferrite, aligned (black dots).
117
ML00006 / Apr.2017
Vibration Induced Fatigue in 304SS
M - Austenitic Stainless SteelP - Longitudinal Seam Welded PipeAp - PipingCd - Vibration Induced Fatigue
Cm - Micrography by OM using A262 Method ADf - Austenite
Micrography transverse to the weld and to the fracture surface (right side of the figure).
116
ML00006 / Apr.2017
Vibration Induced Fatigue in 304SS
M - Austenitic Stainless SteelP - Longitudinal Seam Welded PipeAp - PipingCd - Vibration Induced Fatigue
Cm - Micrography by OM using A262 Method ADf - Fracture
Micrography of the section transverse to the weld and in a region close to the fracture surface (to the right side of the figure).  The secondary fatigue microcracks are associated to the stress concentration raisers of the margin of the weld, irregular.
110
ML00006 / Apr.2017
Vibration Induced Fatigue in 304SS
M - Austenitic Stainless SteelP - Longitudinal Seam Welded PipeAp - PipingCd - Vibration Induced Fatigue
Cm - Micrography by OM using A262 Method ADf - Fatigue Crack
ML00034 — 45 Years Old Acquaduct Grey Cast IronM - Gray Cast ironP - Centrifugally Cast PipeAp - AcquaductCd - General Corrosion
Micrographic detail of the graphite/matrix interface corrosion, leading to a general corrosion loss.
189
ML00034 / Apr.2017
45 Years Old Acquaduct Grey Cast Iron
M - Gray Cast ironP - Centrifugally Cast PipeAp - AcquaductCd - General Corrosion
Cm - Nital Etched Micrography by OMDf - Graphite in Flakes
Micrography of the longitudinal section of the pipe, close to the internal surface, showing graphite in flakes and ferritic matrix with small regions of perlite.
231
ML00034 / Apr.2017
45 Years Old Acquaduct Grey Cast Iron
M - Gray Cast ironP - Centrifugally Cast PipeAp - AcquaductCd - General Corrosion
Cm - Nital Etched Micrography by OMDf - Predominantly Ferritic Matrix
Micrography of the longitudinal section of the pipe, close to the internal surface, showing graphite in flakes and ferritic matrix with small regions of perlite and eutetic in the middle of the perlite colonies.
192
ML00034 / Apr.2017
45 Years Old Acquaduct Grey Cast Iron
M - Gray Cast ironP - Centrifugally Cast PipeAp - AcquaductCd - General Corrosion
Cm - Nital Etched Micrography by OMDf - Predominantly Ferritic Matrix
Micrography of the longitudinal section of the pipe, in the center of the thickness. Graphite in flakes and ferritic matrix with small regions of perlite.
179
ML00034 / Apr.2017
45 Years Old Acquaduct Grey Cast Iron
M - Gray Cast ironP - Centrifugally Cast PipeAp - AcquaductCd - General Corrosion
Cm - Nital Etched Micrography by OMDf - Predominantly Ferritic Matrix
Micrography of the longitudinal section of the pipe, in the center of the thickness. Graphite in flakes and ferritic matrix with small regions of perlite.
162
ML00034 / Apr.2017
45 Years Old Acquaduct Grey Cast Iron
M - Gray Cast ironP - Centrifugally Cast PipeAp - AcquaductCd - General Corrosion
Cm - Nital Etched Micrography by OMDf - Ferrite and Pearlite

+4 more from this case →

ML00005 — Environmental Hydrogen Damage in Ti PipeM - Unalloyed TitaniumP - Longitudinal Seam Welded PipeAp - PipingCd - Hydride Formation
The pipe base metal, at the internal surface, presents a hydride layer showing that the environment is absorbing hydrogen.  Although there are microcracks in this layer it did not detach in the base metal.
102
ML00005 / Apr.2017
Environmental Hydrogen Damage in Ti Pipe
M - Unalloyed TitaniumP - Longitudinal Seam Welded PipeAp - PipingCd - Hydride Formation
Cm - Kroll Etched Micrography by OMDf - Hydride Formation
ML00005 / Apr.2017
Environmental Hydrogen Damage in Ti Pipe
M - Unalloyed TitaniumP - Longitudinal Seam Welded PipeAp - PipingCd - Hydride Formation
Cm - Kroll Etched Micrography by OMDf - Columnar Grains
ML00005 / Apr.2017
Environmental Hydrogen Damage in Ti Pipe
M - Unalloyed TitaniumP - Longitudinal Seam Welded PipeAp - PipingCd - Hydride Formation
Cm - Kroll Etched Micrography by OMDf - Localized Thinning
ML00005 / Apr.2017
Environmental Hydrogen Damage in Ti Pipe
M - Unalloyed TitaniumP - Longitudinal Seam Welded PipeAp - PipingCd - Hydride Formation
Cm - Micrography by OMDf - Brittle Cracks
ML00005 / Apr.2017
Environmental Hydrogen Damage in Ti Pipe
M - Unalloyed TitaniumP - Longitudinal Seam Welded PipeAp - PipingCd - Hydride Formation
Cm - Kroll Etched Micrography by OMDf - Localized Thinning
ML00014 — Pitting Corrosion in 316SS PipeM - Austenitic Stainless SteelP - Seamless PipeAp - FPSOCd - Pitting Corrosion
Austenitic structure at the transverse section of the pipe, free from carbides.
277
ML00014 / Apr.2017
Pitting Corrosion in 316SS Pipe
M - Austenitic Stainless SteelP - Seamless PipeAp - FPSOCd - Pitting Corrosion
Cm - Micrography by OM using A262 Method ADf - Austenite
Austenitic structure, free from carbides, exactly in the region of the pitting, indicating that the corrosion is not associated to the material microstructure.
261
ML00014 / Apr.2017
Pitting Corrosion in 316SS Pipe
M - Austenitic Stainless SteelP - Seamless PipeAp - FPSOCd - Pitting Corrosion
Cm - Micrography by OM using A262 Method ADf - Austenite