Optical Microscope

5 cases · 13 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Application: Piping Detail focus: Damage clear all

Optical Microscope — sub-branches

As polished micrography 1Kroll Etched Micrography by OM 3Micrography by OM 2Micrography by OM using A262 Method A 2NaOH Electrolytic Etched Micro 3Nital Etched Micrography by OM 2

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Micrographic detail of the forging lap defect that appears at the nut surface like a crack, filled with oxides. The nut presented a martensitic structure in the center of the nut, but in the regions adjacent to the defect the structure is ferritic-bainitic due to decarburization. There are several globular oxides (grey spots) that became entrapped during the forging.
654
VIEW
ML00099 / Jan.2018
Forging Defect in a Cadmium Plated Nut
M - Medium Carbon SteelP - NutAp - PipingCd - Fabrication Defect
Cm - Nital Etched Micrography by OMDf - Crack
Micrography transverse to the weld and to the fracture surface (right side of the figure).
116
VIEW
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
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
VIEW
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
Micrography of a transverse section of the pipe, presenting the pitting corrosion. As polished.
310
VIEW
ML00014 / Apr.2017
Pitting Corrosion in 316SS Pipe
M - Austenitic Stainless SteelP - Seamless PipeAp - FPSOCd - Pitting Corrosion
Cm - Micrography by OMDf - Pitting
Macrography transverse to the circunferential weld, longitudinal to the piping, presenting the location, a little far from the welded joint margin, where the through wall cracking is positioned.
160
VIEW
ML00002 / Jan.2018
Preferential Dissolution and Cracks in SDSS
M - Super Duplex Stainless SteelP - Fabrication WeldAp - PipingCd - Preferential Dissolution
Cm - NaOH Electrolytic Etched MicroDf - Through Wall Cracking

More from these cases

ML00099 — Forging Defect in a Cadmium Plated NutM - Medium Carbon SteelP - NutAp - PipingCd - Fabrication Defect
Micrography of the nut in a section transverse to the surface indication. There are several microcracks (parallel and perpendicular to the nut surface) filled with oxides. The nut presented a martensitic microstructure in the center of the thickness and a ferritic-bainitic microstructure at surface and adjacent to the defect, due to decarburization occurred during high temperature forging.
130
VIEW
ML00099 / Jan.2018
Forging Defect in a Cadmium Plated Nut
M - Medium Carbon SteelP - NutAp - PipingCd - Fabrication Defect
Cm - Nital Etched Micrography by OMDf - Crack
Micrographic detail of the lap at the nut surface, as polished. The 20 microns cadmium layer is evident, penetrating in the lap.
46
VIEW
ML00099 / Jan.2018
Forging Defect in a Cadmium Plated Nut
M - Medium Carbon SteelP - NutAp - PipingCd - Fabrication Defect
Cm - As polished micrographyDf - Lap
ML00006 — Vibration Induced Fatigue in 304SSM - Austenitic Stainless SteelP - Longitudinal Seam Welded PipeAp - PipingCd - Vibration Induced Fatigue
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
VIEW
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
ML00005 — Environmental Hydrogen Damage in Ti PipeM - Unalloyed TitaniumP - Longitudinal Seam Welded PipeAp - PipingCd - Hydride Formation
The pipe internal suface, at the welded region, presents no hydride layer (because it has detached) as well as the material itself is suffering brittle detachment.
71
VIEW
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
Detail, as polished, of brittle cracks in the weld metal, from the internal side of the pipe.
67
VIEW
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
Seam weld of the pipe showing the localized thinning in the weld metal, caused by the detachment of the hydride layer and brittle behaviour of the coarse weld metal structure.
64
VIEW
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
ML00002 — Preferential Dissolution and Cracks in SDSSM - Super Duplex Stainless SteelP - Fabrication WeldAp - PipingCd - Preferential Dissolution
Longitudinal section micrography at the cracked position, close to the external surface of the flange, showing cracks transverse to the thickness, associated to the microstructure.
147
VIEW
ML00002 / Jan.2018
Preferential Dissolution and Cracks in SDSS
M - Super Duplex Stainless SteelP - Fabrication WeldAp - PipingCd - Preferential Dissolution
Cm - NaOH Electrolytic Etched MicroDf - Cracks Transverse to the Surface
Longitudinal section micrography at the cracked position, close to the internal surface of the flange (exposed to the corrosive fluid), showing preferential dissolution associated to the microstructure.
133
VIEW
ML00002 / Jan.2018
Preferential Dissolution and Cracks in SDSS
M - Super Duplex Stainless SteelP - Fabrication WeldAp - PipingCd - Preferential Dissolution
Cm - NaOH Electrolytic Etched MicroDf - Preferential Dissolution