Optical Microscope

10 cases · 79 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Product: Raw Material Microstructure: Austenite Standard: A clear all

Optical Microscope — sub-branches

As polished micrography 4Eletrolytically Etched Micrography by OM 6Glyceregia Etched Micrography by OM 6Micrography by OM 8Micrography by OM using A262 Method A 36Nital Etched Micrography by OM 13Oxalic Acid Electrolytic Etch 6

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
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
Micrography of the base metal presenting a banded microstructure in the longitudinal section of the pipe.
51
VIEW
ML00066 / May.2017
GMAW Welded Joint in 9%Ni Alloy Steel
M - Nickel Alloy SteelP - Welded Testpiece for QualificationAp - PipelineCd - Welding
Cm - Nital Etched Micrography by OMDf - Base Metal
Through wall cracking in the longitudinal seam weld of the fitting. Several cracks, longitudinal to the weld, were created by the connection of voids in the weld metal, associated to a strong microstructural evolution.
191
VIEW
ML00061 / Apr.2017
Creep in a Seam Weld of a 304H SS Fitting
M - Austenitic Stainless SteelP - Fabrication WeldAp - Chemical IndustryCd - Creep
Cm - Micrography by OM using A262 Method ADf - Cracks
Micrography of a longitudinal section of the pipe showing that the carbon steel pipe is slightly banded and there is a decarburized layer at the solid solution welded interface. The stainless steel structure (in the right side of the figure) is not revealed using the Nital etch.
125
VIEW
ML00056 / May.2018
Seamless Tube Externally Cladded with SS
M - Carbon Steel / Stainless SteelP - CladdingAp - Pulp and PaperCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Longitudinal Section
The micrography of the transverse section of the plate, as polished, close to the surface. The material presents intergranular corrosion and some grains were lost.
1184
VIEW
ML00015 / Oct.2017
Intergranular Corrosion of 304SS Plate
M - Austenitic Stainless SteelP - Rolled PlateAp - RefineryCd - Intergranular Corrosion
Cm - Micrography by OMDf - Intergranular Corrosion
Micrography of the transverse section of the NEW TUBE, in the center of the thickness, showing the austenitic structure with primary carbides network.
410
VIEW
ML00038 / Apr.2017
Cast SS Tube for High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - Creep
Cm - Glyceregia Etched Micrography by OMDf - Austenitic with Primary Carbides

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
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).
32
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
ML00066 — GMAW Welded Joint in 9%Ni Alloy SteelM - Nickel Alloy SteelP - Welded Testpiece for QualificationAp - PipelineCd - Welding
Micrographic detail of a longitudinal section of the base metal presenting a quenched and tempered microstructure.
49
VIEW
ML00066 / May.2017
GMAW Welded Joint in 9%Ni Alloy Steel
M - Nickel Alloy SteelP - Welded Testpiece for QualificationAp - PipelineCd - Welding
Cm - Nital Etched Micrography by OMDf - Base Metal
Micrographic detail of the low temperature heat affected zone of the pipe. The intercritical temperature (IC) is evident in the decorated grain boundaries of the previous austenite.
42
VIEW
ML00066 / May.2017
GMAW Welded Joint in 9%Ni Alloy Steel
M - Nickel Alloy SteelP - Welded Testpiece for QualificationAp - PipelineCd - Welding
Cm - Nital Etched Micrography by OMDf - Heat Affected Zone
Micrography of the fusion line close to the cap pass (CP). The weld metal (non etched) is in the left side.
43
VIEW
ML00066 / May.2017
GMAW Welded Joint in 9%Ni Alloy Steel
M - Nickel Alloy SteelP - Welded Testpiece for QualificationAp - PipelineCd - Welding
Cm - Nital Etched Micrography by OMDf - Fusion Line
Micrography of the heat affected zone, a little far from the fusion line, close to the base metal.
40
VIEW
ML00066 / May.2017
GMAW Welded Joint in 9%Ni Alloy Steel
M - Nickel Alloy SteelP - Welded Testpiece for QualificationAp - PipelineCd - Welding
Cm - Nital Etched Micrography by OMDf - Heat Affected Zone
Micrographic detail of the fusion line in the center of the thickness, where the heat affected zone was reheated by the subsequent passes.
34
VIEW
ML00066 / May.2017
GMAW Welded Joint in 9%Ni Alloy Steel
M - Nickel Alloy SteelP - Welded Testpiece for QualificationAp - PipelineCd - Welding
Cm - Nital Etched Micrography by OMDf - Fusion Line

+8 more from this case →

ML00061 — Creep in a Seam Weld of a 304H SS FittingM - Austenitic Stainless SteelP - Fabrication WeldAp - Chemical IndustryCd - Creep
Micrography of a longitudinal section of the fitting, at the base metal, presenting an austenitic structure with intergranular and transgranular precipitation as a result of microstructural evolution.
44
VIEW
ML00061 / Apr.2017
Creep in a Seam Weld of a 304H SS Fitting
M - Austenitic Stainless SteelP - Fabrication WeldAp - Chemical IndustryCd - Creep
Cm - Micrography by OM using A262 Method ADf - Base Metal
Micrographic detail of the fitting base metal, presenting an austenitic structure with intergranular and transgranular precipitation as a result of microstructural evolution.
40
VIEW
ML00061 / Apr.2017
Creep in a Seam Weld of a 304H SS Fitting
M - Austenitic Stainless SteelP - Fabrication WeldAp - Chemical IndustryCd - Creep
Cm - Micrography by OM using A262 Method ADf - Base Metal
Micrography of a transverse section of the seam weld, close to the internal surface, presenting several cracks perpendicular to the thickness.
37
VIEW
ML00061 / Apr.2017
Creep in a Seam Weld of a 304H SS Fitting
M - Austenitic Stainless SteelP - Fabrication WeldAp - Chemical IndustryCd - Creep
Cm - Micrography by OM using A262 Method ADf - Close to the Internal Surface
Micrographic detail of the seam weld close to the internal surface, presenting the needles that are the result of microsctructural evolution and cracks filled with oxides.
36
VIEW
ML00061 / Apr.2017
Creep in a Seam Weld of a 304H SS Fitting
M - Austenitic Stainless SteelP - Fabrication WeldAp - Chemical IndustryCd - Creep
Cm - Micrography by OM using A262 Method ADf - Close to the Internal Surface
Micrography of a transverse section of the seam weld, in the middle of the thickness, presenting several parallel cracks.
27
VIEW
ML00061 / Apr.2017
Creep in a Seam Weld of a 304H SS Fitting
M - Austenitic Stainless SteelP - Fabrication WeldAp - Chemical IndustryCd - Creep
Cm - Micrography by OM using A262 Method ADf - In the Center of the Thickness

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ML00056 — Seamless Tube Externally Cladded with SSM - Carbon Steel / Stainless SteelP - CladdingAp - Pulp and PaperCd - Removed From Service
Micrography of a longitudinal section of the pipe showing the carbon steel pipe , internal.
122
VIEW
ML00056 / May.2018
Seamless Tube Externally Cladded with SS
M - Carbon Steel / Stainless SteelP - CladdingAp - Pulp and PaperCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Ferrite and Pearlite
Micrography of a longitudinal section of the pipe showing the stainless steel pipe , external.
99
VIEW
ML00056 / May.2018
Seamless Tube Externally Cladded with SS
M - Carbon Steel / Stainless SteelP - CladdingAp - Pulp and PaperCd - Removed From Service
Cm - Micrography by OM using A262 Method ADf - Austenite
Micrographic detail of the interface in the longitudinal section of the pipe showing the Vickers (300g) microhardness values, close to the interface in the carbon steel side and in the stainless steel side. Although the Nital etch does not allow to reveal the structure in the stainless steel side, the high hardness values show that the structure is different.
113
VIEW
ML00056 / May.2018
Seamless Tube Externally Cladded with SS
M - Carbon Steel / Stainless SteelP - CladdingAp - Pulp and PaperCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Longitudinal Section
Micrographic detail of the interface in the longitudinal section of the pipe showing the decarburized layer at the solid solution welded interface. The stainless steel structure (in the right side of the figure) is not revealed using the Nital etch.
80
VIEW
ML00056 / May.2018
Seamless Tube Externally Cladded with SS
M - Carbon Steel / Stainless SteelP - CladdingAp - Pulp and PaperCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Clad Interface
Micrography of the interface between the carbon steel that is strongly etched by the electrolytic oxalic acid (in the left side of the figure) and the stainless steel, in the longitudinal section of the pipe. There is a strain hardened layer very close to the interface, at the stainless steel side.
79
VIEW
ML00056 / May.2018
Seamless Tube Externally Cladded with SS
M - Carbon Steel / Stainless SteelP - CladdingAp - Pulp and PaperCd - Removed From Service
Cm - Micrography by OM using A262 Method ADf - Longitudinal Section

+2 more from this case →

ML00015 — Intergranular Corrosion of 304SS PlateM - Austenitic Stainless SteelP - Rolled PlateAp - RefineryCd - Intergranular Corrosion
Microstructure of the plate in the center of the ¼” thickness. Equiaxed austenitic grains with delta ferrite stringers and grain boundary carbide precipitation (sensitization).
303
VIEW
ML00015 / Oct.2017
Intergranular Corrosion of 304SS Plate
M - Austenitic Stainless SteelP - Rolled PlateAp - RefineryCd - Intergranular Corrosion
Cm - Micrography by OM using A262 Method ADf - Intergranular Precipitation
Microstructure of the plate in the center of the ¼” thickness. Equiaxed austenitic grains with delta ferrite stringers and grain boundary carbide precipitation (sensitization).
201
VIEW
ML00015 / Oct.2017
Intergranular Corrosion of 304SS Plate
M - Austenitic Stainless SteelP - Rolled PlateAp - RefineryCd - Intergranular Corrosion
Cm - Micrography by OM using A262 Method ADf - Intergranular Precipitation
Micrographic aspect of a longitudinal section of the plate, close to the surface, in a region where it was detected intergranular corrosion up to 0,5 mm depth. As polished.
188
VIEW
ML00015 / Oct.2017
Intergranular Corrosion of 304SS Plate
M - Austenitic Stainless SteelP - Rolled PlateAp - RefineryCd - Intergranular Corrosion
Cm - Micrography by OMDf - Intergranular Corrosion
Micrographic detail of intergranular corrosion, up to 0,5 mm depth. As polished.
171
VIEW
ML00015 / Oct.2017
Intergranular Corrosion of 304SS Plate
M - Austenitic Stainless SteelP - Rolled PlateAp - RefineryCd - Intergranular Corrosion
Cm - Micrography by OMDf - Intergranular Corrosion
Micrographic aspect of a longitudinal section of the plate, close to the surface, in a region with intergranular corrosion. Several loose grains were removed, indicating that the structure was embrittled by the intergranular corrosion.
171
VIEW
ML00015 / Oct.2017
Intergranular Corrosion of 304SS Plate
M - Austenitic Stainless SteelP - Rolled PlateAp - RefineryCd - Intergranular Corrosion
Cm - Micrography by OM using A262 Method ADf - Intergranular Corrosion

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ML00038 — Cast SS Tube for High Temperature ServiceM - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - Creep
Micrography of the transverse section of the NEW TUBE, close to the external surface, showing the austenitic structure with primary carbides network.
59
VIEW
ML00038 / Apr.2017
Cast SS Tube for High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - Creep
Cm - Glyceregia Etched Micrography by OMDf - Close to the External Surface
The micrography in the as polished condition of the NEW TUBE shows that there are no casting defects close to the external surface.
49
VIEW
ML00038 / Apr.2017
Cast SS Tube for High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - Creep
Cm - Micrography by OMDf - Close to the External Surface
The micrography in the as polished condition of the NEW TUBE shows that there are no casting defects in the center of the thickness.
47
VIEW
ML00038 / Apr.2017
Cast SS Tube for High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - Creep
Cm - Micrography by OMDf - Transverse Section
Micrography of the transverse section of the TUBE REMOVED FROM SERVICE, in the center of the thickness, showing the austenitic structure with primary carbides network and secondary precipitation.
59
VIEW
ML00038 / Apr.2017
Cast SS Tube for High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - Creep
Cm - Glyceregia Etched Micrography by OMDf - Intragranular Secondary Precipitation
Micrography of the transverse section of the TUBE REMOVED FROM SERVICE,close to the external surface, showing the austenitic structure with coalesced carbides and secondary precipitation.
40
VIEW
ML00038 / Apr.2017
Cast SS Tube for High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - Creep
Cm - Glyceregia Etched Micrography by OMDf - Close to the External Surface

+2 more from this case →