Optical Microscope

20 cases · 157 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Product: Raw Material Microstructure: Austenite clear all

Optical Microscope — sub-branches

As polished micrography 4Chromic Acid Electrolytic Etched 6Eletrolytically Etched Micrography by OM 6Glyceregia Etched Micrography by OM 6Kalling Etched Micrography by OM 27Micrography by OM 12Micrography by OM using A262 Method A 42Nital Etched Micrography by OM 27Oxalic Acid Electrolytic Etch 27

Results

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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
Optical micrography of the transverse section of the drill collar, in the center of the thickness, presenting an uniform, granular, fully austenitic microstructure.
76
VIEW
ML00135 / May.2018
MIC of a Non Magnetic Drilling Tool
M - High Mn Austenitic SteelP - Tubular ForgingAp - O&G Well DrillingCd - Pitting Corrosion
Cm - Oxalic Acid Electrolytic EtchDf - Transverse Section
Image by scanning electron microscopy of the metallurgically bonded interface of the internally cladded pipe. It is a longitudinal seam welded pipe, with substrate in low alloy steel X65 and clad plate in Alloy 625 (welded by a solid state process). The region is a detail in the side of the Ni alloy clad plate where a grain refinement has occurred probably due to recrystallization of a strain hardened region during later heat treatment. The microhardness of this region is a lot higher than the value obtained out of this region, in the clad plate.
904
VIEW
ML00133 / May.2018
Seam Welded Pipe Cladded with Alloy 625
M - LAS / Ni AlloyP - Longitudinal Seam Welded PipeAp - Oil and GasCd - Welding
Cm - Oxalic Acid Electrolytic EtchDf - Clad Interface
Micrography of a longitudinal section of the pipe substrate, in low magnification, showing a uniform microstructure,
79
VIEW
ML00132 / May.2018
Seamless Pipe Overlaid with Alloy 625
M - LAS / Ni AlloyP - Seamless PipeAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Base Metal
Micrography of the 1.65 mm thickness tube, in the middle of the thickness of the longitudinal section. This part of the tube is located in the colder part of the equipment, position 1. The material presented carbide precipitation at grain boundaries (not yet fully surrounding the grains) and at this point the tube presented no internal corrosion.
338
VIEW
ML00086 / Nov.2017
Intergranular Corrosion of Sensitized 304SS
M - Austenitic Stainless SteelP - Seamless tubeAp - Heat ExchangerCd - Intergranular Corrosion
Cm - Micrography by OM using A262 Method ADf - Austenite
Micrography of the new tube close to a region of a casting defect (shrinkage), presenting only austenitic structure with a network of primary precipitates.
351
VIEW
ML00097 / Nov.2017
Cast SS Tube Removed From High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - High Temperature
Cm - Glyceregia Etched Micrography by OMDf - Austenitic with Primary Carbides
Micrographic detail of the austenitic structure at the surface, where the grain size of the material increased. By optical microscopy the intragranular precipitation due to solution annealing and aging is not revealed.
794
VIEW
ML00089 / Sep.2017
Inconel 718 Allen Bolt for Subsea Application
M - NiCrFe AlloyP - Machined PartAp - SubseaCd - Typical manufacturing
Cm - Kalling Etched Micrography by OMDf - Austenite
Micrography of the longitudinal section of the forging material, presenting a granular austenite, precipitation hardened.
84
VIEW
ML00078 / Jun.2017
Hydrogen Cracking of IN 718 Subsea Connector
M - NiCrFe AlloyP - ForgingAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Longitudinal Section

More from these cases

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
ML00135 — MIC of a Non Magnetic Drilling ToolM - High Mn Austenitic SteelP - Tubular ForgingAp - O&G Well DrillingCd - Pitting Corrosion
Optical micrography of the transverse section of the drill collar, in the center of the thickness, presenting an uniform, granular, fully austenitic microstructure.
64
VIEW
ML00135 / May.2018
MIC of a Non Magnetic Drilling Tool
M - High Mn Austenitic SteelP - Tubular ForgingAp - O&G Well DrillingCd - Pitting Corrosion
Cm - Oxalic Acid Electrolytic EtchDf - Transverse Section
Micrographic detail of the transverse section of the drill collar, in the center of the thickness, presenting an uniform, granular, fully austenitic microstructure.
61
VIEW
ML00135 / May.2018
MIC of a Non Magnetic Drilling Tool
M - High Mn Austenitic SteelP - Tubular ForgingAp - O&G Well DrillingCd - Pitting Corrosion
Cm - Oxalic Acid Electrolytic EtchDf - Austenite
Optical micrography of the longitudinal section of the drill collar, in the center of the thickness, presenting slightly elongated grains of fully austenitic microstructure, cold worked. The material presented 38HRc hardness.
58
VIEW
ML00135 / May.2018
MIC of a Non Magnetic Drilling Tool
M - High Mn Austenitic SteelP - Tubular ForgingAp - O&G Well DrillingCd - Pitting Corrosion
Cm - Oxalic Acid Electrolytic EtchDf - Longitudinal Section
Optical micrography of the longitudinal section of the drill collar, in the center of the thickness, presenting slightly elongated grains of fully austenitic microstructure, cold worked.
62
VIEW
ML00135 / May.2018
MIC of a Non Magnetic Drilling Tool
M - High Mn Austenitic SteelP - Tubular ForgingAp - O&G Well DrillingCd - Pitting Corrosion
Cm - Oxalic Acid Electrolytic EtchDf - Longitudinal Section
Micrographic detail of the longitudinal section of the drill collar, in the center of the thickness, presenting slightly elongated grains of fully austenitic microstructure, cold worked.
59
VIEW
ML00135 / May.2018
MIC of a Non Magnetic Drilling Tool
M - High Mn Austenitic SteelP - Tubular ForgingAp - O&G Well DrillingCd - Pitting Corrosion
Cm - Oxalic Acid Electrolytic EtchDf - Austenite

+6 more from this case →

ML00133 — Seam Welded Pipe Cladded with Alloy 625M - LAS / Ni AlloyP - Longitudinal Seam Welded PipeAp - Oil and GasCd - Welding
Micrography of a longitudinal section of the pipe substrate, in low magnification, showing a uniform microstructure,
51
VIEW
ML00133 / May.2018
Seam Welded Pipe Cladded with Alloy 625
M - LAS / Ni AlloyP - Longitudinal Seam Welded PipeAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Base Metal
Micrography of a longitudinal section of the pipe substrate showing a uniform bainitic microstructure obtained by the pipe quenching and tempering,
48
VIEW
ML00133 / May.2018
Seam Welded Pipe Cladded with Alloy 625
M - LAS / Ni AlloyP - Longitudinal Seam Welded PipeAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Longitudinal Section
Micrographic detail of a longitudinal section of the pipe substrate showing a uniform bainitic microstructure,
50
VIEW
ML00133 / May.2018
Seam Welded Pipe Cladded with Alloy 625
M - LAS / Ni AlloyP - Longitudinal Seam Welded PipeAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Bainite
Micrography of a longitudinal section of the pipe at the interface with the clad plate, with Nital etch that reveals only the low alloy steel structure, to the left side of the image.
55
VIEW
ML00133 / May.2018
Seam Welded Pipe Cladded with Alloy 625
M - LAS / Ni AlloyP - Longitudinal Seam Welded PipeAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Clad Interface
Micrography of a longitudinal section of the pipe at the interface with the clad plate, with Nital etch that reveals only the low alloy steel structure, to the left side of the image.
51
VIEW
ML00133 / May.2018
Seam Welded Pipe Cladded with Alloy 625
M - LAS / Ni AlloyP - Longitudinal Seam Welded PipeAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Clad Interface

+10 more from this case →

ML00132 — Seamless Pipe Overlaid with Alloy 625M - LAS / Ni AlloyP - Seamless PipeAp - Oil and GasCd - Welding
Micrography of a longitudinal section of the pipe substrate showing a uniform bainitic microstructure obtained by the pipe quenching and tempering,
72
VIEW
ML00132 / May.2018
Seamless Pipe Overlaid with Alloy 625
M - LAS / Ni AlloyP - Seamless PipeAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Longitudinal Section
Micrographic detail of a longitudinal section of the pipe substrate showing a uniform bainitic microstructure.
68
VIEW
ML00132 / May.2018
Seamless Pipe Overlaid with Alloy 625
M - LAS / Ni AlloyP - Seamless PipeAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Bainite
Micrography of a longitudinal section of the pipe at the overlay fusion line, with Nital etch that reveals only the low alloy steel structure, to the left side of the image.
67
VIEW
ML00132 / May.2018
Seamless Pipe Overlaid with Alloy 625
M - LAS / Ni AlloyP - Seamless PipeAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Clad Interface
Micrography of a longitudinal section of the pipe at the overlay fusion line, with Nital etch that reveals only the low alloy steel structure, to the left side of the image. Some decarburization of the low alloy steel substrate is evident since the microstructure is slightly different a little far from the interface.
66
VIEW
ML00132 / May.2018
Seamless Pipe Overlaid with Alloy 625
M - LAS / Ni AlloyP - Seamless PipeAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Clad Interface
Micrographic detail of a longitudinal section of the pipe at the interface with the clad plate, with Nital etch that reveals only the low alloy steel structure, to the left side of the image.
59
VIEW
ML00132 / May.2018
Seamless Pipe Overlaid with Alloy 625
M - LAS / Ni AlloyP - Seamless PipeAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Clad Interface

+7 more from this case →

ML00086 — Intergranular Corrosion of Sensitized 304SSM - Austenitic Stainless SteelP - Seamless tubeAp - Heat ExchangerCd - Intergranular Corrosion
Micrography of the 1.65 mm thickness tube, in the middle of the thickness of the longitudinal section. This part of the tube is located in position 2, where the temperature was higher and the carbide precipitation increased during service.
272
VIEW
ML00086 / Nov.2017
Intergranular Corrosion of Sensitized 304SS
M - Austenitic Stainless SteelP - Seamless tubeAp - Heat ExchangerCd - Intergranular Corrosion
Cm - Micrography by OM using A262 Method ADf - Intergranular Precipitation
Micrography of the 1.65 mm thickness tube, in the middle of the thickness of the longitudinal section. This part of the tube is located in position 3, where intergranular and transgranular carbide precipitation occurred during service.
234
VIEW
ML00086 / Nov.2017
Intergranular Corrosion of Sensitized 304SS
M - Austenitic Stainless SteelP - Seamless tubeAp - Heat ExchangerCd - Intergranular Corrosion
Cm - Micrography by OM using A262 Method ADf - Intragranular Secondary Precipitation
Micrography of a longitudinal section of the tube in position 2, presenting thinning by intergranular corrosion at the internal surface.
193
VIEW
ML00086 / Nov.2017
Intergranular Corrosion of Sensitized 304SS
M - Austenitic Stainless SteelP - Seamless tubeAp - Heat ExchangerCd - Intergranular Corrosion
Cm - Micrography by OM using A262 Method ADf - Intergranular Corrosion
Micrographic detail of the intergranular corrosion at the internal surface of the tube in position 2. Several grains were already removed by the corrosion.
171
VIEW
ML00086 / Nov.2017
Intergranular Corrosion of Sensitized 304SS
M - Austenitic Stainless SteelP - Seamless tubeAp - Heat ExchangerCd - Intergranular Corrosion
Cm - Micrography by OM using A262 Method ADf - Intergranular Corrosion
Micrography of a longitudinal section of the tube in position 3, at the internal surface. Although there is a strong precipitation, both intergranular and transgranular, the tube did not corrode at this point.
144
VIEW
ML00086 / Nov.2017
Intergranular Corrosion of Sensitized 304SS
M - Austenitic Stainless SteelP - Seamless tubeAp - Heat ExchangerCd - Intergranular Corrosion
Cm - Micrography by OM using A262 Method ADf - Intragranular Secondary Precipitation

+1 more from this case →

ML00097 — Cast SS Tube Removed From High Temperature ServiceM - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - High Temperature
Micrography close to the external surface of a new tube, sound.
48
VIEW
ML00097 / Nov.2017
Cast SS Tube Removed From High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - High Temperature
Cm - As polished micrographyDf - Close to the External Surface
Micrography close to the internal surface of a new tube, presenting casting defects.
47
VIEW
ML00097 / Nov.2017
Cast SS Tube Removed From High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - High Temperature
Cm - As polished micrographyDf - Close to the Internal Surface
Micrography of the tube removed from service after 6 month, close to a region of a casting defect (shrinkage), presenting austenitic structure with a network of primary precipitates (initial stage of coarsening) and intragranular secondary precipitation.
48
VIEW
ML00097 / Nov.2017
Cast SS Tube Removed From High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - High Temperature
Cm - Glyceregia Etched Micrography by OMDf - Intragranular Secondary Precipitation
Micrography close to the internal surface of the tube removed from service after 6 month, presenting high temperature oxidation and shrinkage voids (casting defects).
31
VIEW
ML00097 / Nov.2017
Cast SS Tube Removed From High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - High Temperature
Cm - As polished micrographyDf - Close to the Internal Surface
Micrography close to the external surface of the tube removed from service, damaged by high temperature oxidation.
25
VIEW
ML00097 / Nov.2017
Cast SS Tube Removed From High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - High Temperature
Cm - As polished micrographyDf - Close to the External Surface
ML00089 — Inconel 718 Allen Bolt for Subsea ApplicationM - NiCrFe AlloyP - Machined PartAp - SubseaCd - Typical manufacturing
The micrography of a longitudinal section of the bolt close to the surface, at the thread, shows that it was machined from a bar, not rolled.
37
VIEW
ML00089 / Sep.2017
Inconel 718 Allen Bolt for Subsea Application
M - NiCrFe AlloyP - Machined PartAp - SubseaCd - Typical manufacturing
Cm - Kalling Etched Micrography by OMDf - Machined Thread
The micrography of a longitudinal section of the bolt, in the center of the thickness (ND 1/2"), shows an equiaxial granular structure. Although the material was hardened by heat treatment (solution annealing and aging), the microstructure at this magnification does not reveal the intragranular precipitation.
34
VIEW
ML00089 / Sep.2017
Inconel 718 Allen Bolt for Subsea Application
M - NiCrFe AlloyP - Machined PartAp - SubseaCd - Typical manufacturing
Cm - Kalling Etched Micrography by OMDf - Equiaxial Grains
Micrographic detail of a longitudinal section of the bolt, close to the surface (ND 1/2"). The grain size is higher than the center of the bolt.
28
VIEW
ML00089 / Sep.2017
Inconel 718 Allen Bolt for Subsea Application
M - NiCrFe AlloyP - Machined PartAp - SubseaCd - Typical manufacturing
Cm - Kalling Etched Micrography by OMDf - Austenite
ML00078 — Hydrogen Cracking of IN 718 Subsea ConnectorM - NiCrFe AlloyP - ForgingAp - SubseaCd - Hydrogen Embrittlement
Micrography of the longitudinal section of the conector, at the fracture position, showing secondary cracks from the fracture surface.
64
VIEW
ML00078 / Jun.2017
Hydrogen Cracking of IN 718 Subsea Connector
M - NiCrFe AlloyP - ForgingAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Fracture
The micrographic detail of the longitudinal section at the fracture surface shows intergranular morphology for the secondary cracks (longitudinal to the forging axis).
64
VIEW
ML00078 / Jun.2017
Hydrogen Cracking of IN 718 Subsea Connector
M - NiCrFe AlloyP - ForgingAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Secondary Cracks
Micrographic detail of a longitudinal section of the connector, at the fracture surface (in the top), showing intergranular secondary cracks.
54
VIEW
ML00078 / Jun.2017
Hydrogen Cracking of IN 718 Subsea Connector
M - NiCrFe AlloyP - ForgingAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Intergranular Cracking
Micrographic detail of a longitudinal section of the connector, at the fracture surface (in the top), showing intergranular secondary cracks. There is a large amount of delta phase precipitated intergranular and intragranluar.
48
VIEW
ML00078 / Jun.2017
Hydrogen Cracking of IN 718 Subsea Connector
M - NiCrFe AlloyP - ForgingAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Secondary Cracks