Optical Microscope

22 cases · 188 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Product: Finished Product Condition: Corrosion clear all

Optical Microscope — sub-branches

As polished micrography 10Chromic Acid Electrolytic Etched 1Eletrolytically Etched Micrography by OM 5FeCl3+HCl+Ethanol Etched Micro 1FeCl3+HCl+H2O Etched Micro 2Glyceregia Etched Micrography by OM 1H2SO4+HNO3+H3PO4 Etched Micro 1Kalling Etched Micrography by OM 44Micrography by OM 10Micrography by OM using A262 Method A 20NaOH Electrolytic Etched Micro 13Nital Etched Micrography by OM 53Oxalic Acid Electrolytic Etch 27

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Metallographic image of a longitudinal section of the clamp (axis in the vertical direction), showing a refined ferritic perlitic structure.
34
VIEW
ML00171 / Feb.2021
Corrosion Fatigue of U Bolt Pipe Clamp
M - Low Carbon SteelP - BoltAp - ShipCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Longitudinal Section
Micrography presenting a uniform and refined tempered martensitic structure.
39
VIEW
ML00169 / Nov.2020
Drill Pipe Fracture in the Pipe Body
M - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Uniform Structure
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
Optical micrography of a longitudinal section of the fractured bolt, at the thread. The material is austenitic, free from carbides, and the threads were almost removed by the stress corrosion cracks.
756
VIEW
ML00157 / Feb.2020
Bolts Under Chloride SCC Conditions
M - Austenitic Stainless SteelP - BoltAp - Oil and GasCd - Stress Corrosion
Cm - Oxalic Acid Electrolytic EtchDf - Stress Corrosion Cracks
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
Microstructure of the spring in a transverse section, presenting an aged martensitic structure.
96
VIEW
ML00137 / Mar.2021
Brittle Fracture of a 15-5 PH Valve Spring
M - Precipitation Hardened Stainless SteelP - SpringAp - Oil and GasCd - Brittle Behavior
Cm - Kalling Etched Micrography by OMDf - Martensite
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
As polished micrographic aspect of the longitudinal section of the cylinder, at the surface, in a region where the damage is in the begining. It is possible to see that there are two layers at the surface. A first Ni layer, 300HV average hardness, over the low carbon steel substrate, 200HV average hardness, and a chromium plated layer, 1100HV average hardness and several discontinuities.
62
VIEW
ML00128 / Apr.2018
MIC of a Stored Hydraulic Cylinder
M - Low Carbon SteelP - Chromium PlatedAp - OffshoreCd - Localized Dissolution
Cm - Micrography by OMDf - Longitudinal Section

More from these cases

ML00171 — Corrosion Fatigue of U Bolt Pipe ClampM - Low Carbon SteelP - BoltAp - ShipCd - Corrosion Fatigue
Metallographic detail of the longitudinal section of the clamp with a ferritic pearlitic structure.
32
VIEW
ML00171 / Feb.2021
Corrosion Fatigue of U Bolt Pipe Clamp
M - Low Carbon SteelP - BoltAp - ShipCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Ferrite and Pearlite
Metallographic detail of the ferritic perlitic structure.
31
VIEW
ML00171 / Feb.2021
Corrosion Fatigue of U Bolt Pipe Clamp
M - Low Carbon SteelP - BoltAp - ShipCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Ferrite and Pearlite
Metallographic aspect of a longitudinal section of the clamp, at the surface (left side of the image) showing a region where there are corrosion pits in the carbon steel clamp, due to the lack of protection by the coating, and the propagation of small transgranular cracks from to the surface.
30
VIEW
ML00171 / Feb.2021
Corrosion Fatigue of U Bolt Pipe Clamp
M - Low Carbon SteelP - BoltAp - ShipCd - Corrosion Fatigue
Cm - Micrography by OMDf - Crack
The clamp presented several cracks, parallel, transverse to the axis. The appearance of the cracks in the metallographic section shows that some cracks propagate and growth with a irregular path.
24
VIEW
ML00171 / Feb.2021
Corrosion Fatigue of U Bolt Pipe Clamp
M - Low Carbon SteelP - BoltAp - ShipCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Longitudinal Section
Metallographic aspect of the cracks showing that several microcracks join from different pits and growth through the section, in a transgranular morphologyy.
26
VIEW
ML00171 / Feb.2021
Corrosion Fatigue of U Bolt Pipe Clamp
M - Low Carbon SteelP - BoltAp - ShipCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Transgranular Cracking

+2 more from this case →

ML00169 — Drill Pipe Fracture in the Pipe BodyM - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Corrosion Fatigue
Micrography presenting a uniform and refined tempered martensitic structure.
39
VIEW
ML00169 / Nov.2020
Drill Pipe Fracture in the Pipe Body
M - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Martensite
Micrographic detail of the tempered martensite.
40
VIEW
ML00169 / Nov.2020
Drill Pipe Fracture in the Pipe Body
M - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Martensite
Micrography of a longitudinal section of the pipe, at the external pipe surface, where there is a corroded spot. The microstructure is tempered martensite and at the surface the pipe is slightly decarburized.
28
VIEW
ML00169 / Nov.2020
Drill Pipe Fracture in the Pipe Body
M - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - External Surface
Micrography of a longitudinal section of the pipe, at the external pipe surface, where there is a crack propagating from the corroded spot. The microstructure is tempered martensite and at the surface the pipe is slightly decarburized.
27
VIEW
ML00169 / Nov.2020
Drill Pipe Fracture in the Pipe Body
M - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Crack
Micrographic detail of the crack from the corroded spot.
28
VIEW
ML00169 / Nov.2020
Drill Pipe Fracture in the Pipe Body
M - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Corrosion

+7 more from this case →

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 →

ML00157 — Bolts Under Chloride SCC ConditionsM - Austenitic Stainless SteelP - BoltAp - Oil and GasCd - Stress Corrosion
Low magnification micrography, by optical microscope, of the longitudinal section of a damaged bolt, in the center of the thickness. The microstructure is austenitic, free from carbides.
100
VIEW
ML00157 / Feb.2020
Bolts Under Chloride SCC Conditions
M - Austenitic Stainless SteelP - BoltAp - Oil and GasCd - Stress Corrosion
Cm - Oxalic Acid Electrolytic EtchDf - Austenite
Micrography, by optical microscope, of the longitudinal section of a damaged bolt, in the center of the thickness. The microstructure is austenitic, free from carbides, strain hardened. The hardness values of the material are from 200HV1 to 300HV1, that meets the class 2 of strenght (ASTM A193 B8M class 2).
79
VIEW
ML00157 / Feb.2020
Bolts Under Chloride SCC Conditions
M - Austenitic Stainless SteelP - BoltAp - Oil and GasCd - Stress Corrosion
Cm - Nital Etched Micrography by OMDf - Strain Hardened
Detail of the strain hardened austenitic microstructure. Micrography by optical microscope, of the longitudinal section of a bolt, in the center of the thickness.
76
VIEW
ML00157 / Feb.2020
Bolts Under Chloride SCC Conditions
M - Austenitic Stainless SteelP - BoltAp - Oil and GasCd - Stress Corrosion
Cm - Oxalic Acid Electrolytic EtchDf - Strain Hardened
Optical micrography of a longitudinal section of the fractured bolt, at the thread. The material is austenitic, free from carbides, and the threads were fully cracked by the stress corrosion mechanism.
58
VIEW
ML00157 / Feb.2020
Bolts Under Chloride SCC Conditions
M - Austenitic Stainless SteelP - BoltAp - Oil and GasCd - Stress Corrosion
Cm - Oxalic Acid Electrolytic EtchDf - Stress Corrosion Cracks
Optical micrography of a longitudinal section of the fractured bolt, under the thread, showing stress corrosion cracks through the section.
46
VIEW
ML00157 / Feb.2020
Bolts Under Chloride SCC Conditions
M - Austenitic Stainless SteelP - BoltAp - Oil and GasCd - Stress Corrosion
Cm - Oxalic Acid Electrolytic EtchDf - Stress Corrosion Cracks

+2 more from this case →

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 →

ML00137 — Brittle Fracture of a 15-5 PH Valve SpringM - Precipitation Hardened Stainless SteelP - SpringAp - Oil and GasCd - Brittle Behavior
Micrography of a longitudinal section of the spring indicating that under the deposits there are intergranular cracks initiating at the spring surface.
72
VIEW
ML00137 / Mar.2021
Brittle Fracture of a 15-5 PH Valve Spring
M - Precipitation Hardened Stainless SteelP - SpringAp - Oil and GasCd - Brittle Behavior
Cm - As polished micrographyDf - Intergranular Cracking
Micrographic detail of a longitudinal section of the spring indicating that under the deposits there are intergranular cracks initiating at the spring surface.
65
VIEW
ML00137 / Mar.2021
Brittle Fracture of a 15-5 PH Valve Spring
M - Precipitation Hardened Stainless SteelP - SpringAp - Oil and GasCd - Brittle Behavior
Cm - As polished micrographyDf - Intergranular Cracking
Micrographic detail of a longitudinal section of the spring indicating that under the deposits there are intergranular cracks initiating at the spring surface.
60
VIEW
ML00137 / Mar.2021
Brittle Fracture of a 15-5 PH Valve Spring
M - Precipitation Hardened Stainless SteelP - SpringAp - Oil and GasCd - Brittle Behavior
Cm - Kalling Etched Micrography by OMDf - Intergranular Cracking
Micrography of a longitudinal section of the spring indicating that under the deposits there are intergranular cracks initiating at the spring surface.
57
VIEW
ML00137 / Mar.2021
Brittle Fracture of a 15-5 PH Valve Spring
M - Precipitation Hardened Stainless SteelP - SpringAp - Oil and GasCd - Brittle Behavior
Cm - Kalling Etched Micrography by OMDf - Intergranular Cracking
Micrographic detail of a longitudinal section of the spring indicating that under the deposits there are intergranular cracks initiating at the spring surface.
57
VIEW
ML00137 / Mar.2021
Brittle Fracture of a 15-5 PH Valve Spring
M - Precipitation Hardened Stainless SteelP - SpringAp - Oil and GasCd - Brittle Behavior
Cm - Kalling Etched Micrography by OMDf - Intergranular Cracking

+7 more from this case →

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 →

ML00128 — MIC of a Stored Hydraulic CylinderM - Low Carbon SteelP - Chromium PlatedAp - OffshoreCd - Localized Dissolution
Micrographic aspect of the Cr layer at the surface presenting incipient damage. Microcracks of the Cr layer, associated to small pits.
62
VIEW
ML00128 / Apr.2018
MIC of a Stored Hydraulic Cylinder
M - Low Carbon SteelP - Chromium PlatedAp - OffshoreCd - Localized Dissolution
Cm - Micrography by OMDf - Cracks
Micrographic aspect, after Nital etching, of the longitudinal section of the cylinder, at the surface, in a region where the damage is in the begining. There are two layers at the surface. A first Ni layer, 160 microns thick and 300HV average hardness, over the low carbon steel substrate, 200HV average hardness, and a chromium plated layer, 250 microns thick and 1100HV average hardness.
59
VIEW
ML00128 / Apr.2018
MIC of a Stored Hydraulic Cylinder
M - Low Carbon SteelP - Chromium PlatedAp - OffshoreCd - Localized Dissolution
Cm - Nital Etched Micrography by OMDf - Corrosion
Micrographic detail of the longitudinal section of the cylinder, at the surface, in a region where the Cr layer is detaching.
56
VIEW
ML00128 / Apr.2018
MIC of a Stored Hydraulic Cylinder
M - Low Carbon SteelP - Chromium PlatedAp - OffshoreCd - Localized Dissolution
Cm - Nital Etched Micrography by OMDf - Corrosion
Micrographic aspect of the longitudinal section of the cylinder steel substrate, presenting a ferritic-pearlitic structure.
207
VIEW
ML00128 / Apr.2018
MIC of a Stored Hydraulic Cylinder
M - Low Carbon SteelP - Chromium PlatedAp - OffshoreCd - Localized Dissolution
Cm - Nital Etched Micrography by OMDf - Ferrite and Pearlite
Micrographic detail of the ferritic-pearlitic structure of the cylinder steel substrate.
41
VIEW
ML00128 / Apr.2018
MIC of a Stored Hydraulic Cylinder
M - Low Carbon SteelP - Chromium PlatedAp - OffshoreCd - Localized Dissolution
Cm - Nital Etched Micrography by OMDf - Ferrite and Pearlite

+3 more from this case →