Optical Microscope

100 cases · 889 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

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Optical Microscope — sub-branches

As polished micrography 67Chromic Acid Electrolytic Etched 1Eletrolytically Etched Micrography by OM 11FeCl3+HCl+Ethanol Etched Micro 15FeCl3+HCl+H2O Etched Micro 28Glyceregia Etched Micrography by OM 1H2SO4+HNO3+H3PO4 Etched Micro 1Kalling Etched Micrography by OM 190Keller Etched Micrography by OM 31Kroll Etched Micrography by OM 5Micro by OM, HCl + Ethanol + Picric Acid 12Micrography by OM 41Micrography by OM using A262 Method A 68Micrography by OM, HF + HNO3 + H2O etch 8NH4OH+H2O+H2O2 Etched Micro 8NaOH Electrolytic Etched Micro 82Nital Etched Micrography by OM 300Oxalic Acid Electrolytic Etch 20

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The stub end was manufactured from a plate and the microstructure in a longitudial section shows a refined granular austenitic structure.
62
VIEW
ML00168 / Aug.2020
SCC of Austenitic SS Flange Stub End
M - Austenitic Stainless SteelP - Stub EndAp - Chemical IndustryCd - Stress Corrosion
Cm - Oxalic Acid Electrolytic EtchDf - Longitudinal Section
Micrography of a longitudinal section of the tubing showing a granular structure, austenitic.
52
VIEW
ML00167 / Aug.2020
Fatigue of a Flared Tubing Connection
M - Austenitic Stainless SteelP - TubingAp - EngineCd - Mechanical Fatigue
Cm - Oxalic Acid Electrolytic EtchDf - Longitudinal Section
Low magnification micrography of a transverse section of the ring showing a dendritic structure.
64
VIEW
ML00166 / Jul.2020
Tin Bronze Wear Ring of Seawater Pump
M - Tin BronzeP - Wear RingAp - ShipCd - Removed From Service
Cm - FeCl3+HCl+H2O Etched MicroDf - Dendritic
Micrography of the tranverse section of the tube, in the center of the thickness. There are small grains and large grains, characterizing a dual grain size. The large grains size is about 100 microns, more than 10 times larger than the average size of the smaller grains size.
101
VIEW
ML00165 / Jul.2020
SCC of Aluminum Bronze Heating Coil
M - Aluminum BronzeP - Seamless tubeAp - Oil and GasCd - Stress Corrosion
Cm - FeCl3+HCl+H2O Etched MicroDf - Dual grain sizes
Micrography of a longitudinal section, in the center of the valve body, solid 3" thickness. The structure is austenitic with delta ferrite in interdendritic spaces.
67
VIEW
ML00164 / Jun.2020
Austenitic SS Casting for Valve Body
M - Austenitic Stainless SteelP - CastingAp - ValveCd - Typical manufacturing
Cm - Oxalic Acid Electrolytic EtchDf - Austenite
Micrography of a wire in a longitudinal section, presenting a predominantly oearlitic structure, highly strained. The wires did not present any coating.
104
VIEW
ML00155 / Jan.2020
Failure of a Prestressed Concrete Steel Strand
M - High Carbon SteelP - Wire RopeAp - StructureCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Longitudinal Section
Metallographic aspect of the polished surface of the (back of the) coaster, showing pores and shrinkages, typical of a casting structure.
49
VIEW
ML00156 / Jan.2020
Antique Silver Plated Decorative Piece
M - BrassP - Decorative PieceAp - OrnamentalCd - Non Destructive Examination
Cm - As polished micrographyDf - Casting Structure
Micrography of a crankshaft longitudinal section at the shaft edge, in the as polished condition, presenting nodular graphite, well distruibuted.
139
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - As polished micrographyDf - At the Surface

More from these cases

ML00168 — SCC of Austenitic SS Flange Stub EndM - Austenitic Stainless SteelP - Stub EndAp - Chemical IndustryCd - Stress Corrosion
Micrography of a longitudinal section of the stub end showing a refined austenitic structure.
57
VIEW
ML00168 / Aug.2020
SCC of Austenitic SS Flange Stub End
M - Austenitic Stainless SteelP - Stub EndAp - Chemical IndustryCd - Stress Corrosion
Cm - Oxalic Acid Electrolytic EtchDf - Austenite
Micrographic detail of the austenitic structure. Free from grain boundaries carbide precipitation.
54
VIEW
ML00168 / Aug.2020
SCC of Austenitic SS Flange Stub End
M - Austenitic Stainless SteelP - Stub EndAp - Chemical IndustryCd - Stress Corrosion
Cm - Oxalic Acid Electrolytic EtchDf - Austenite
Micrography of the stub end, external side to the top, presenting multiple cracks propagating throught wall.
48
VIEW
ML00168 / Aug.2020
SCC of Austenitic SS Flange Stub End
M - Austenitic Stainless SteelP - Stub EndAp - Chemical IndustryCd - Stress Corrosion
Cm - As polished micrographyDf - Close to the External Surface
Micrography of the stub end longitudinal section, presenting multiple cracks, branched.
40
VIEW
ML00168 / Aug.2020
SCC of Austenitic SS Flange Stub End
M - Austenitic Stainless SteelP - Stub EndAp - Chemical IndustryCd - Stress Corrosion
Cm - As polished micrographyDf - Multiple cracks
Micrography of the stub end close to the external surface, outer diameter in the top of the image, presenting multiple cracks starting fro the surface and propagating into the thickness, through wall.
32
VIEW
ML00168 / Aug.2020
SCC of Austenitic SS Flange Stub End
M - Austenitic Stainless SteelP - Stub EndAp - Chemical IndustryCd - Stress Corrosion
Cm - Oxalic Acid Electrolytic EtchDf - Close to the External Surface

+4 more from this case →

ML00167 — Fatigue of a Flared Tubing ConnectionM - Austenitic Stainless SteelP - TubingAp - EngineCd - Mechanical Fatigue
Micrography of a longitudinal section of the tubing, showing the austenitic structure free from strain hardening and free from grain boundary carbides.
51
VIEW
ML00167 / Aug.2020
Fatigue of a Flared Tubing Connection
M - Austenitic Stainless SteelP - TubingAp - EngineCd - Mechanical Fatigue
Cm - Oxalic Acid Electrolytic EtchDf - Austenite
Micrographic detail of the austenitic structure, free from strain hardening and free from grain boundary carbides.
54
VIEW
ML00167 / Aug.2020
Fatigue of a Flared Tubing Connection
M - Austenitic Stainless SteelP - TubingAp - EngineCd - Mechanical Fatigue
Cm - Oxalic Acid Electrolytic EtchDf - Austenite
Micrography of a longitudinal section of the tubing where the fracture occurred. the left side is the outer diameter and the right side is the inner diameter.
37
VIEW
ML00167 / Aug.2020
Fatigue of a Flared Tubing Connection
M - Austenitic Stainless SteelP - TubingAp - EngineCd - Mechanical Fatigue
Cm - Oxalic Acid Electrolytic EtchDf - At the Surface
Micrography of a longitudinal section of the flared tubing where the fracture occurred. The starting point of the fracture is associated to the external side of the tubing, where it was connected by a nut and there was a localized plastic deformation due to the fitting assembly.
33
VIEW
ML00167 / Aug.2020
Fatigue of a Flared Tubing Connection
M - Austenitic Stainless SteelP - TubingAp - EngineCd - Mechanical Fatigue
Cm - Oxalic Acid Electrolytic EtchDf - Transgranular Fracture
Micrographic detail of the localized plastic deformation due to the fitting assembly, in the region where the fatigue has started.
30
VIEW
ML00167 / Aug.2020
Fatigue of a Flared Tubing Connection
M - Austenitic Stainless SteelP - TubingAp - EngineCd - Mechanical Fatigue
Cm - Oxalic Acid Electrolytic EtchDf - Plastic Deformation
ML00166 — Tin Bronze Wear Ring of Seawater PumpM - Tin BronzeP - Wear RingAp - ShipCd - Removed From Service
Micrography of a transverse section of the ring showing a cored alpha structure with segregation at interdendritic regions. This structure is in a region close to the ring surface.
52
VIEW
ML00166 / Jul.2020
Tin Bronze Wear Ring of Seawater Pump
M - Tin BronzeP - Wear RingAp - ShipCd - Removed From Service
Cm - FeCl3+HCl+H2O Etched MicroDf - Dendritic
Micrography of a transverse section of the ring showing a cored alpha structure with strong segregation at interdendritic regions, and regions of a white structure at grain boundaries. This structure is in a region close to the center of the ring.
51
VIEW
ML00166 / Jul.2020
Tin Bronze Wear Ring of Seawater Pump
M - Tin BronzeP - Wear RingAp - ShipCd - Removed From Service
Cm - FeCl3+HCl+H2O Etched MicroDf - Dendritic
Micrographic detail of the cored alpha structure with light segregation at intergranular regions (light layer at grain boundaries), and a white euctetoid structure (alpha and delta) at interdendritic space. This structure is in a region close to the ring surface, where the solidification was quicker.
49
VIEW
ML00166 / Jul.2020
Tin Bronze Wear Ring of Seawater Pump
M - Tin BronzeP - Wear RingAp - ShipCd - Removed From Service
Cm - FeCl3+HCl+H2O Etched MicroDf - Grain boundary intermetallics
Micrographic detail of the cored alpha structure with strong segregation at intergranular regions (dark layer at grain boundaries), and a white euctetoid structure (alpha and delta) at interdendritic space. This structure is in a region close to the center of the ring, where the solidification was slower.
47
VIEW
ML00166 / Jul.2020
Tin Bronze Wear Ring of Seawater Pump
M - Tin BronzeP - Wear RingAp - ShipCd - Removed From Service
Cm - FeCl3+HCl+H2O Etched MicroDf - Grain boundary intermetallics
Tin Bronze Wear Ring of Seawater Pump
2
VIEW
ML00166 / Jul.2020
Tin Bronze Wear Ring of Seawater Pump
M - Tin BronzeP - Wear RingAp - ShipCd - Removed From Service
Cm - FeCl3+HCl+H2O Etched MicroDf - General View

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ML00165 — SCC of Aluminum Bronze Heating CoilM - Aluminum BronzeP - Seamless tubeAp - Oil and GasCd - Stress Corrosion
Micrographic detail of the alpha microstructure presenting dual grain sizes. Two different types of twins are presented in the structure: annealing twins and deformation twins, suggesting that the material was probably partially recristalized after cold deformation and stress relief treatment.
87
VIEW
ML00165 / Jul.2020
SCC of Aluminum Bronze Heating Coil
M - Aluminum BronzeP - Seamless tubeAp - Oil and GasCd - Stress Corrosion
Cm - FeCl3+HCl+H2O Etched MicroDf - Alpha
Micrography of a transverse section of the bent tube, external surface (OD) to the top and internal surface (ID) to the bottom of the figure. At the through wall cracking position, the external surface presented a layer of intergranular corrosion.
95
VIEW
ML00165 / Jul.2020
SCC of Aluminum Bronze Heating Coil
M - Aluminum BronzeP - Seamless tubeAp - Oil and GasCd - Stress Corrosion
Cm - As polished micrographyDf - Cracking
Micrographic detail of the external side of the bent tube, as polished, showing detachement of several grains due to the intergranular corrosion layer. The corroded layer is about 200 microns thick at this position.
89
VIEW
ML00165 / Jul.2020
SCC of Aluminum Bronze Heating Coil
M - Aluminum BronzeP - Seamless tubeAp - Oil and GasCd - Stress Corrosion
Cm - As polished micrographyDf - Intergranular Corrosion
Micrographic detail of the external side of the tube, showing the layer of intergranular corrosion and the through ewall integranular stress corrosion cracking.
88
VIEW
ML00165 / Jul.2020
SCC of Aluminum Bronze Heating Coil
M - Aluminum BronzeP - Seamless tubeAp - Oil and GasCd - Stress Corrosion
Cm - As polished micrographyDf - Through Wall Cracking
Micrography of the external side of the bent tube, showing detachement of several grains due to intergranular corrosion. The corroded layer is about 200 microns thick at this position. The differences of colours in the corroded layer suggests a dealloying effect, also known as selective leaching.
71
VIEW
ML00165 / Jul.2020
SCC of Aluminum Bronze Heating Coil
M - Aluminum BronzeP - Seamless tubeAp - Oil and GasCd - Stress Corrosion
Cm - FeCl3+HCl+H2O Etched MicroDf - External Surface

+4 more from this case →

ML00164 — Austenitic SS Casting for Valve BodyM - Austenitic Stainless SteelP - CastingAp - ValveCd - Typical manufacturing
Micrography of a longitudinal section, in the center of the valve body. The structure is austenitic with delta ferrite in interdendritic spaces. The austenite presents a cored matrix in the dendrites, indicating the chemical composition was not homogeneized during the heat treatment.
60
VIEW
ML00164 / Jun.2020
Austenitic SS Casting for Valve Body
M - Austenitic Stainless SteelP - CastingAp - ValveCd - Typical manufacturing
Cm - Oxalic Acid Electrolytic EtchDf - Delta ferrite
Micrographic detail of the cored austenitic structure with delta ferrite in interdendritic spaces. The chemical composition was not homogeneized during the heat treatment.
55
VIEW
ML00164 / Jun.2020
Austenitic SS Casting for Valve Body
M - Austenitic Stainless SteelP - CastingAp - ValveCd - Typical manufacturing
Cm - Oxalic Acid Electrolytic EtchDf - Delta ferrite
Micrography of a longitudinal section, in the 1" thickness valve wall. The structure is austenitic with delta ferrite in interdendritic spaces.
48
VIEW
ML00164 / Jun.2020
Austenitic SS Casting for Valve Body
M - Austenitic Stainless SteelP - CastingAp - ValveCd - Typical manufacturing
Cm - Oxalic Acid Electrolytic EtchDf - Austenite
Micrography of a longitudinal section, in the valve wall 1" thick. The structure is austenitic with delta ferrite in interdendritic spaces. The austenite is clean indicating that the homogeneization of a smaller thickness in the heat treatment is considered effective.
40
VIEW
ML00164 / Jun.2020
Austenitic SS Casting for Valve Body
M - Austenitic Stainless SteelP - CastingAp - ValveCd - Typical manufacturing
Cm - Oxalic Acid Electrolytic EtchDf - Delta ferrite
Micrographic detail of the clean austenitic matrix, with delta ferrite in interdendritic spaces.
35
VIEW
ML00164 / Jun.2020
Austenitic SS Casting for Valve Body
M - Austenitic Stainless SteelP - CastingAp - ValveCd - Typical manufacturing
Cm - Oxalic Acid Electrolytic EtchDf - Delta ferrite
ML00155 — Failure of a Prestressed Concrete Steel StrandM - High Carbon SteelP - Wire RopeAp - StructureCd - Corrosion Fatigue
Higher magnification detail of the predominantly pearlitic microstructure of the wire.
88
VIEW
ML00155 / Jan.2020
Failure of a Prestressed Concrete Steel Strand
M - High Carbon SteelP - Wire RopeAp - StructureCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Predominantly Pearlitic
Micrography of a typical corroded wire, in a longitudinal section, showing loss of thickness by corrosion. The microstructure of the wire is predominantly pearlitic and the wire presents no coating, in any region.
54
VIEW
ML00155 / Jan.2020
Failure of a Prestressed Concrete Steel Strand
M - High Carbon SteelP - Wire RopeAp - StructureCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Corrosion
Micrography of a typical corrosion-fatigue mechanism, in a longitudinal section. The loss of material is accelerated a lot by the cracks through the thickness.
42
VIEW
ML00155 / Jan.2020
Failure of a Prestressed Concrete Steel Strand
M - High Carbon SteelP - Wire RopeAp - StructureCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Cracks
Micrography of a typical overloaded wire, in a longitudinal section, showing plastic deformation and necking at the fracture. About 25% of the wires have ruptured by this ductile mechanism.
34
VIEW
ML00155 / Jan.2020
Failure of a Prestressed Concrete Steel Strand
M - High Carbon SteelP - Wire RopeAp - StructureCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Ductile Fracture
Micrography of a typical as polished overloaded wire, in a longitudinal section, showing necking at the fracture and secondary ductile cracks. About 25% of the wires have ruptured by this ductile mechanism.
35
VIEW
ML00155 / Jan.2020
Failure of a Prestressed Concrete Steel Strand
M - High Carbon SteelP - Wire RopeAp - StructureCd - Corrosion Fatigue
Cm - As polished micrographyDf - Ductile Fracture

+10 more from this case →

ML00156 — Antique Silver Plated Decorative PieceM - BrassP - Decorative PieceAp - OrnamentalCd - Non Destructive Examination
Same region of the previous image but is a higher magnification, showing the metallographic aspect of the polished surface of the (back of the) coaster. Shrinkage with a dendritic morphology typical of a casting structure.
48
VIEW
ML00156 / Jan.2020
Antique Silver Plated Decorative Piece
M - BrassP - Decorative PieceAp - OrnamentalCd - Non Destructive Examination
Cm - As polished micrographyDf - Voids
Low magnification metallography of the coaster after etching, revealing a casting structure of alpha plus beta phases. Beta is the dark brown matrix phase and alpha is the dendritic yellow phase.
45
VIEW
ML00156 / Jan.2020
Antique Silver Plated Decorative Piece
M - BrassP - Decorative PieceAp - OrnamentalCd - Non Destructive Examination
Cm - NH4OH+H2O+H2O2 Etched MicroDf - Alpha and Beta
Metallography of the coaster after etching, revealing a casting structure of alpha plus beta phases. Beta is the dark brown matrix phase and alpha is the dendritic yellow phase.
48
VIEW
ML00156 / Jan.2020
Antique Silver Plated Decorative Piece
M - BrassP - Decorative PieceAp - OrnamentalCd - Non Destructive Examination
Cm - NH4OH+H2O+H2O2 Etched MicroDf - Alpha and Beta
High magnification metallography of the coaster after etching, revealing a casting structure of alpha plus beta phases. Beta is the dark brown matrix phase and alpha is the dendritic yellow phase. The non destructive preparation created a metallographic surface not well polished (full of grinding scratches).
48
VIEW
ML00156 / Jan.2020
Antique Silver Plated Decorative Piece
M - BrassP - Decorative PieceAp - OrnamentalCd - Non Destructive Examination
Cm - NH4OH+H2O+H2O2 Etched MicroDf - Alpha and Beta
ML00154 — High Strength Cast Iron CrankshaftM - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
As polished micrography of the crankshaft at the shaft edge, close to the surface. Graphite in nodules.
126
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - As polished micrographyDf - Graphite in Nodules
As polished micrographic detail of the graphite in nodules, close to the surface of the shaft edge, in a longitudinal section.
114
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - As polished micrographyDf - Graphite in Nodules
Micrography of the crankshaft at the surface, in the radio that is not heat treated. The microstructure is nodules of graphite in a ferritic and pearlitic matrix, predominantly pearlitic.
96
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by OMDf - At the Surface
Micrography of the crankshaft close to the radio that is not heat treated. Graphite in nodules and a ferritic and pearlitic matrix, predominantly pearlitic.
81
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by OMDf - Matrix of ferrite and pearlite
Micrographic detail of the graphite nodules and a ferritic and pearlitic matrix, predominantly pearlitic.
82
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by OMDf - Matrix of ferrite and pearlite

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