Optical Microscope

4 cases · 32 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Microstructure: Coarse Structure clear all

Optical Microscope — sub-branches

As polished micrography 1FeCl3+HCl+H2O Etched Micro 7NaOH Electrolytic Etched Micro 6Nital Etched Micrography by OM 9Oxalic Acid Electrolytic Etch 9

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Micrographic aspect of the tube out of the damaged region, in a longitudinal section, showing the grain refined copper structure.
96
VIEW
ML00180 / Mar.2022
Local Melting of Copper Cooling Tubes
M - Pure CopperP - Cooling TubeAp - SiderurgyCd - Overheating
Cm - FeCl3+HCl+H2O Etched MicroDf - In the Center of the Thickness
Sample surface. Microstructure of the plate base metal, exposed to high temperature exhausting gases. Refined austenite and some cracks.
24
VIEW
ML00174 / Jul.2021
Carburization of a 347 SS Welded Joint
M - Austenitic Stainless SteelP - Fabrication WeldAp - EnergyCd - Carburization
Cm - Oxalic Acid Electrolytic EtchDf - Base Metal
The longitudinal section of the shaft, in the center of the thickness, shows a coarse structure, and a ferritic/bainitic structure with pearlite islands.
97
VIEW
ML00152 / Dec.2018
Low Alloy Steel Pump Shaft
M - High Strength Low AlloyP - ShaftAp - Oil and GasCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Longitudinal Section
Micrography of a transverse section of the forged bar in the center of the thickness. Ferrite and austenite. Coarse structure.
74
VIEW
ML00123 / Feb.2018
Non Qualified Superduplex for Subsea
M - Super Duplex Stainless SteelP - BarAp - Oil and GasCd - Not according to spec
Cm - NaOH Electrolytic Etched MicroDf - Transverse Section

More from these cases

ML00180 — Local Melting of Copper Cooling TubesM - Pure CopperP - Cooling TubeAp - SiderurgyCd - Overheating
Micrographic detail of the granular copper structure, a little far from the overheated region.
102
VIEW
ML00180 / Mar.2022
Local Melting of Copper Cooling Tubes
M - Pure CopperP - Cooling TubeAp - SiderurgyCd - Overheating
Cm - FeCl3+HCl+H2O Etched MicroDf - Granular structure
Micrographic detail of the granular copper structure, out of the damaged area. The dark particles are non metallic (oxides).
93
VIEW
ML00180 / Mar.2022
Local Melting of Copper Cooling Tubes
M - Pure CopperP - Cooling TubeAp - SiderurgyCd - Overheating
Cm - FeCl3+HCl+H2O Etched MicroDf - Granular structure
Micrographic aspect, as polished, of a transverse section of the tube (bottom side of the image, orange), at the interface between the tube and the melted steel over the external diameter (top side of the image, grey). In the copper tube there are several microcracks and regions of incipient melting (voids).
41
VIEW
ML00180 / Mar.2022
Local Melting of Copper Cooling Tubes
M - Pure CopperP - Cooling TubeAp - SiderurgyCd - Overheating
Cm - As polished micrographyDf - Cracks
Micrographic aspect of the tube wall under the localized thinning, in a transverse section, showing a coarse structure due to high temperature grain growth.
37
VIEW
ML00180 / Mar.2022
Local Melting of Copper Cooling Tubes
M - Pure CopperP - Cooling TubeAp - SiderurgyCd - Overheating
Cm - FeCl3+HCl+H2O Etched MicroDf - Overheating
Micrographic detail of the high temperature grain growth in the tube microstructure.
31
VIEW
ML00180 / Mar.2022
Local Melting of Copper Cooling Tubes
M - Pure CopperP - Cooling TubeAp - SiderurgyCd - Overheating
Cm - FeCl3+HCl+H2O Etched MicroDf - Coarse Structure

+6 more from this case →

ML00174 — Carburization of a 347 SS Welded JointM - Austenitic Stainless SteelP - Fabrication WeldAp - EnergyCd - Carburization
Detailed microstructure of the plate base metal, exposed to high temperature exhausting gases. Refined austenite, precipitation of carbides in the grain boumdaries and some cracks.
23
VIEW
ML00174 / Jul.2021
Carburization of a 347 SS Welded Joint
M - Austenitic Stainless SteelP - Fabrication WeldAp - EnergyCd - Carburization
Cm - Oxalic Acid Electrolytic EtchDf - Austenite
Detailed microstructure of the plate base metal, exposed to high temperature exhausting gases. Refined austenite, precipitation of carbides in the grain boumdaries and some cracks.
24
VIEW
ML00174 / Jul.2021
Carburization of a 347 SS Welded Joint
M - Austenitic Stainless SteelP - Fabrication WeldAp - EnergyCd - Carburization
Cm - Oxalic Acid Electrolytic EtchDf - Crack
Sample surface. Microstructure of the weld metal, exposed to high temperature exhausting gases. Austeno-ferritic structure and some cracks.
20
VIEW
ML00174 / Jul.2021
Carburization of a 347 SS Welded Joint
M - Austenitic Stainless SteelP - Fabrication WeldAp - EnergyCd - Carburization
Cm - Oxalic Acid Electrolytic EtchDf - Weld Metal
Detailed microstructure of the weld metal, exposed to high temperature exhausting gases. Austeno-ferritic structure and some cracks.
21
VIEW
ML00174 / Jul.2021
Carburization of a 347 SS Welded Joint
M - Austenitic Stainless SteelP - Fabrication WeldAp - EnergyCd - Carburization
Cm - Oxalic Acid Electrolytic EtchDf - Ferrite and Austenite
Detailed microstructure of the weld metal, exposed to high temperature exhausting gases. Austeno-ferritic structure, strong carbide precipitation integranular and transgranular, and some cracks.
23
VIEW
ML00174 / Jul.2021
Carburization of a 347 SS Welded Joint
M - Austenitic Stainless SteelP - Fabrication WeldAp - EnergyCd - Carburization
Cm - Oxalic Acid Electrolytic EtchDf - Cracks

+3 more from this case →

ML00152 — Low Alloy Steel Pump ShaftM - High Strength Low AlloyP - ShaftAp - Oil and GasCd - Removed From Service
The coarse structure in the center of the shaft thickness is evidenced by free ferrite islands at the previous austenite grains. The presence of a pearlitic structure evidences the slow cool of the material.
85
VIEW
ML00152 / Dec.2018
Low Alloy Steel Pump Shaft
M - High Strength Low AlloyP - ShaftAp - Oil and GasCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Coarse Structure
The longitudinal section of the shaft, at the surface, also shows a coarse structure, and a ferritic/bainitic structure with pearlite islands. There is only a small refining in the previous austenite grain boundaries, indicating that the material was not heat treated.
75
VIEW
ML00152 / Dec.2018
Low Alloy Steel Pump Shaft
M - High Strength Low AlloyP - ShaftAp - Oil and GasCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Longitudinal Section
The longitudinal section of the shaft, at the surface, presenting only a small refining in the previous austenite grain boundaries than in the center, indicating that the material was slowed colled from forming and not heat treated.
67
VIEW
ML00152 / Dec.2018
Low Alloy Steel Pump Shaft
M - High Strength Low AlloyP - ShaftAp - Oil and GasCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Coarse Structure
Micrographic detail of the pearlitic structure at the surface of the shaft thickness.
69
VIEW
ML00152 / Dec.2018
Low Alloy Steel Pump Shaft
M - High Strength Low AlloyP - ShaftAp - Oil and GasCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Pearlite
ML00123 — Non Qualified Superduplex for SubseaM - Super Duplex Stainless SteelP - BarAp - Oil and GasCd - Not according to spec
Micrography of a longitudinal section of the forged bar in the center of the thickness. Ferrite and austenite. Coarse structure.
61
VIEW
ML00123 / Feb.2018
Non Qualified Superduplex for Subsea
M - Super Duplex Stainless SteelP - BarAp - Oil and GasCd - Not according to spec
Cm - NaOH Electrolytic Etched MicroDf - Longitudinal Section
Micrography of a transverse section of the forged bar in the center of the thickness. Ferrite and austenite. The ferrite amount, measured by metallographic method, manual counting, is 59%.
53
VIEW
ML00123 / Feb.2018
Non Qualified Superduplex for Subsea
M - Super Duplex Stainless SteelP - BarAp - Oil and GasCd - Not according to spec
Cm - NaOH Electrolytic Etched MicroDf - Transverse Section
Micrography of a longitudinal section of the forged bar in the center of the thickness. Ferrite and austenite. The average austenite spacing is 80 microns, a lot larger than the maximum allowed in the specification, of 30 microns. No detrimental phases were identified at the ferrite/austenite interfaces, but the ferrite phase presented a rough aspect. Higher magnification analysis would be required to identify precipitation.
53
VIEW
ML00123 / Feb.2018
Non Qualified Superduplex for Subsea
M - Super Duplex Stainless SteelP - BarAp - Oil and GasCd - Not according to spec
Cm - NaOH Electrolytic Etched MicroDf - Longitudinal Section
Micrographic detail of the ferrite and austenite structure in the transverse section of the forged bar, in the center of the thickness.
53
VIEW
ML00123 / Feb.2018
Non Qualified Superduplex for Subsea
M - Super Duplex Stainless SteelP - BarAp - Oil and GasCd - Not according to spec
Cm - NaOH Electrolytic Etched MicroDf - Ferrite and Austenite
Micrographic detail of the ferrite and austenite structure in the longitudinal section of the forged bar, in the center of the thickness.
55
VIEW
ML00123 / Feb.2018
Non Qualified Superduplex for Subsea
M - Super Duplex Stainless SteelP - BarAp - Oil and GasCd - Not according to spec
Cm - NaOH Electrolytic Etched MicroDf - Ferrite and Austenite