Optical Microscope

183 cases · 1637 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Optical Microscope — sub-branches

As polished micrography 128Chromic Acid Electrolytic Etched 7Eletrolytically Etched Micrography by OM 11FeCl3+HCl+Ethanol Etched Micro 15FeCl3+HCl+H2O Etched Micro 28Glyceregia Etched Micrography by OM 7H2SO4+HNO3+H3PO4 Etched Micro 4Kalling Etched Micrography by OM 202Keller Etched Micrography by OM 58Kroll Etched Micrography by OM 15Micro by OM, HCl + Ethanol + Picric Acid 12Micro by OM, picric acid+FeCl3+H2O etch 4Micrography by OM 73Micrography by OM using A262 Method A 80Micrography by OM, HF + HNO3 + H2O etch 8NH4OH+H2O+H2O2 Etched Micro 8NaOH Electrolytic Etched Micro 108Nital Etched Micrography by OM 801Oxalic Acid Electrolytic Etch 68

Results

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Micrography of the tool steel, in the longitudinal section of the part. The material presented a uniform structure, tempered martensite. The tempering was in low temperature since the hardness is high (58 HRc at the surface).
87
VIEW
ML00084 / Mar.2020
Walrus Tool Steel
M - High Carbon Tool SteelP - ForgingAp - Mechanical IndustryCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Uniform Structure
Micrography of the tubing fusion line. The welding was conducted in two passes. The average hardness at the heat affected zone of the tubing is 257 HV5.
825
VIEW
ML00100 / Nov.2017
Superduplex Tubing to Forging Welded Joint
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Welding
Cm - NaOH Electrolytic Etched MicroDf - Fusion Line Left Side
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 of a transverse section of the lifting part, showing interdendritic voids close to the surface at the inner diameter of the padeye. The microstructure is tempered martensite.
450
VIEW
ML00098 / Nov.2017
Brittle Fracture of a Casting Lifting Device
M - Low Alloy Medium Carbon QTP - CastingAp - LiftingCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Casting defects
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 external surface of the tubular equipment, close to the fracture position (it is to the top of the figure), showing multiple cracks, typical of a corrosion fatigue mechanism.
861
VIEW
ML00082 / Dec.2017
Corrosion Fatigue of a Drilling Tool
M - Low Alloy Medium Carbon QTP - Tubular ForgingAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Multiple cracks
Micrographic detail of a transverse section of the rail, in the head, showing a fully perlitic structure.
520
VIEW
ML00096 / Oct.2017
Carbon Steel Tee Rail
M - High Strength Low AlloyP - RailAp - TransportationCd - Typical manufacturing
Cm - Nital Etched Micrography by OMDf - Pearlite
Micrography of a transverse section of the engine bearing, close to the internal surface, showing two layers of bearing alloys that presents a total thickness of 600 microns.
29
VIEW
ML00083 / Oct.2017
Steel Back of a Bimetallic Engine Bearing
M - Low Carbon SteelP - Cold FormedAp - ShipCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Surface Layer

More from these cases

ML00084 — Walrus Tool SteelM - High Carbon Tool SteelP - ForgingAp - Mechanical IndustryCd - Removed From Service
Micrographic detail of the tool steel, in the longitudinal section of the part. The material presented a uniform structure, tempered martensite, with small secondary carbides. The hardness in the section is 59 HRc.
73
VIEW
ML00084 / Mar.2020
Walrus Tool Steel
M - High Carbon Tool SteelP - ForgingAp - Mechanical IndustryCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Martensite
ML00100 — Superduplex Tubing to Forging Welded JointM - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Welding
Micrography of the tubing heat affected zone.
69
VIEW
ML00100 / Nov.2017
Superduplex Tubing to Forging Welded Joint
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Welding
Cm - NaOH Electrolytic Etched MicroDf - HAZ Left Side
Micrography of the tubing heat affected zone.
68
VIEW
ML00100 / Nov.2017
Superduplex Tubing to Forging Welded Joint
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Welding
Cm - NaOH Electrolytic Etched MicroDf - HAZ Left Side
Low magnification micrography of the superduplex stainless steel tubing (base metal), in the longitudinal direction. Refined ferritic-austenitic structure. The average hardness in the section is 264HV5.
58
VIEW
ML00100 / Nov.2017
Superduplex Tubing to Forging Welded Joint
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Welding
Cm - NaOH Electrolytic Etched MicroDf - Base Metal Left Side
Micrography of the superduplex stainless steel tubing (base metal), in the longitudinal direction. Refined ferritic-austenitic structure.
55
VIEW
ML00100 / Nov.2017
Superduplex Tubing to Forging Welded Joint
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Welding
Cm - NaOH Electrolytic Etched MicroDf - Duplex structure
Micrographic detail of the superduplex stainless steel tubing (base metal), in the longitudinal direction. Refined ferritic-austenitic structure.
53
VIEW
ML00100 / Nov.2017
Superduplex Tubing to Forging Welded Joint
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Welding
Cm - NaOH Electrolytic Etched MicroDf - Duplex structure

+10 more from this case →

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
Tempered martensitic microstructure in the transverse section of the nut, in the center. The material presented 29 HRc that is typical of a quenched and tempered steel.
30
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 - Martensite
Ferritic-bainitic microstructure in the transverse section of the nut, at the surface where the cadmium plate is also evident. The nut surface presents a decarburized layer and the lap entrapped oxides.
30
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 - Bainitic Ferrite
ML00098 — Brittle Fracture of a Casting Lifting DeviceM - Low Alloy Medium Carbon QTP - CastingAp - LiftingCd - Brittle Fracture
Micrography of the lifting padeye showing a dendritic path of a quenched and tempered martensitic microstructure. The segregated regions (white interdendritic regions) are more clearly identified in low magnification. Voids are located in these segregated regions.
21
VIEW
ML00098 / Nov.2017
Brittle Fracture of a Casting Lifting Device
M - Low Alloy Medium Carbon QTP - CastingAp - LiftingCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Martensite
Micrography of the lifting padeye showing a quenched and tempered martensitic microstructure. Voids are located in interdendritic segregated regions.
20
VIEW
ML00098 / Nov.2017
Brittle Fracture of a Casting Lifting Device
M - Low Alloy Medium Carbon QTP - CastingAp - LiftingCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Martensite
Micrography of the lifting padeye showing a quenched and tempered martensitic microstructure. Voids are located in interdendritic segregated regions. At this magnification the segregation is not clear.
16
VIEW
ML00098 / Nov.2017
Brittle Fracture of a Casting Lifting Device
M - Low Alloy Medium Carbon QTP - CastingAp - LiftingCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Martensite
Micrography of the lifting padeye showing a quenched and tempered martensitic microstructure. The hardness level of the material is about 39 HRc.
14
VIEW
ML00098 / Nov.2017
Brittle Fracture of a Casting Lifting Device
M - Low Alloy Medium Carbon QTP - CastingAp - LiftingCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Martensite
Micrography of the secondary crack, paralel to fracture, starting from the internal diameter of the padeye. The crack propagates in an interdendritic morphology, interconnecting casting defects.
13
VIEW
ML00098 / Nov.2017
Brittle Fracture of a Casting Lifting Device
M - Low Alloy Medium Carbon QTP - CastingAp - LiftingCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Secondary Cracks

+8 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
ML00082 — Corrosion Fatigue of a Drilling ToolM - Low Alloy Medium Carbon QTP - Tubular ForgingAp - O&G Well DrillingCd - Corrosion Fatigue
Micrographic aspect of the martensitic structure at the longitudinal section.
60
VIEW
ML00082 / Dec.2017
Corrosion Fatigue of a Drilling Tool
M - Low Alloy Medium Carbon QTP - Tubular ForgingAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Martensite
Micrography of the quenched and tempered structure. Longitudinal section.
51
VIEW
ML00082 / Dec.2017
Corrosion Fatigue of a Drilling Tool
M - Low Alloy Medium Carbon QTP - Tubular ForgingAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Banded Structure
Micrography of the quenched and tempered structure. Longitudinal section. Sligthly banded.
45
VIEW
ML00082 / Dec.2017
Corrosion Fatigue of a Drilling Tool
M - Low Alloy Medium Carbon QTP - Tubular ForgingAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Banded Structure
As polished micrography of the external surface of the tubular equipment, close to the fracture position (it is to the top of the figure), showing corrosion fatigue cracks. These are multiple cracks, paralel to the main fracture, slightly branched and fully filled with oxides.
51
VIEW
ML00082 / Dec.2017
Corrosion Fatigue of a Drilling Tool
M - Low Alloy Medium Carbon QTP - Tubular ForgingAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - As polished micrographyDf - Multiple cracks
As polished micrography of the external surface of the tubular equipment, close to the fracture position (it is to the top of the figure), showing corrosion fatigue cracks. These are multiple cracks, paralel to the main fracture, slightly branched and fully filled with oxides.
43
VIEW
ML00082 / Dec.2017
Corrosion Fatigue of a Drilling Tool
M - Low Alloy Medium Carbon QTP - Tubular ForgingAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - As polished micrographyDf - Multiple cracks

+2 more from this case →

ML00096 — Carbon Steel Tee RailM - High Strength Low AlloyP - RailAp - TransportationCd - Typical manufacturing
Micrographic detail of a transverse section of the rail, in the head, showing a fully perlitic structure.
57
VIEW
ML00096 / Oct.2017
Carbon Steel Tee Rail
M - High Strength Low AlloyP - RailAp - TransportationCd - Typical manufacturing
Cm - Nital Etched Micrography by OMDf - Perlite
Micrography of a transverse section of the rail, in the head, showing equiaxial grains. Perlitic microstructure.
54
VIEW
ML00096 / Oct.2017
Carbon Steel Tee Rail
M - High Strength Low AlloyP - RailAp - TransportationCd - Typical manufacturing
Cm - Nital Etched Micrography by OMDf - Transverse Section
ML00083 — Steel Back of a Bimetallic Engine BearingM - Low Carbon SteelP - Cold FormedAp - ShipCd - Removed From Service
Micrographic detail of a transverse section of the back steel of an engine bearing, presenting a predominantly ferritic structure, strain hardened.
26
VIEW
ML00083 / Oct.2017
Steel Back of a Bimetallic Engine Bearing
M - Low Carbon SteelP - Cold FormedAp - ShipCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Predominantly Ferritic
Micrography of a transverse section of the back steel of an engine bearing, presenting a predominantly ferritic structure, strain hardened.
24
VIEW
ML00083 / Oct.2017
Steel Back of a Bimetallic Engine Bearing
M - Low Carbon SteelP - Cold FormedAp - ShipCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Strain Hardened
Micrography of a transverse section of the back steel of an engine bearing, presenting a predominantly ferritic structure, strain hardened.
24
VIEW
ML00083 / Oct.2017
Steel Back of a Bimetallic Engine Bearing
M - Low Carbon SteelP - Cold FormedAp - ShipCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Strain Hardened