Microstructure

98 cases · 329 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Capture method: Nital Etched Micrography by OM clear all

Microstructure — sub-branches

Acicular Ferrite 1Bainite 14Bainitic Ferrite 7Bainitic HAZ 6Bainitic Martensitic 5Banded Pearlite 7Banded Structure 18Carburized Layer 4Clad Interface 10Coalesced structure 6Coarse Structure 4Coating Layer 3Columnar Grains 1Decarburized Surface 1Duplex structure 1Equiaxial Grains 1Ferrite 3Ferrite and Bainite 3Ferrite and Pearlite 55Ferritic Weld Metal 2Free Carbides in Pearlite Colonies 1Fusion Line 8Grain refined structure 10Granular structure 1Graphite Type A (ASTM A247) 1Graphite in Flakes 3Graphite in Imperfect Nodules 1Graphite in Nodules 4Hard Chromium Layer 1Martensite 70Matrix of ferrite and pearlite 5Mixture of Melted Metals 3Ni layer 2No Coating Layer 3Non Metallic Inclusions 3Overheating 1Overtempered Structure 1Pearlite 10Pearlite Matrix 3Predominantly Ferritic 15Predominantly Pearlitic 5Strain Hardened 9Strain hardened pearlite 4Tempered Martensite 4Tempered Structure 1Uniform Structure 4Zn Layer 4

Results

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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
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 tube microstructure is ferritic-pearlitic, typical of this kind of material. No evidences of microstrutural changes were detected (no overheating, no decarburization).
177
VIEW
ML00163 / Jun.2020
Corrosion Fatigue of a Boiler Waterwall Tube
M - Low Carbon SteelP - Seamless tubeAp - BoilerCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Ferrite and Pearlite
Low magnification micrography of a longitudinal section of the valve body, in the center of the thickness. As expected for this high strength steel, the microstructure is martensitic, but with segregation bands.
48
VIEW
ML00162 / Apr.2020
Valve Body Crack Growth from Weld Defects
M - Low Alloy Medium Carbon QTP - Valve BodyAp - O&G Well DrillingCd - Fatigue Induced by a Defect
Cm - Nital Etched Micrography by OMDf - Banded Structure
Micrography of a longitudinal section of the socket at the position where the fracture occurred. Uniform tempered martensitic structure. The hardness of this microstructure is 639 HV1Kg.
74
VIEW
ML00161 / Mar.2020
Brittle Fracture of a High Strength Socket
M - Medium Carbon Tool SteelP - ToolAp - Oil and GasCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Martensite
Tempered martensite of the pipe body of this API 5D grade S135 drill pipe. The material presents, at this low magnification micrographic aspect, a slightly banded structure, usual for this type of drill pipe.
58
VIEW
ML00159 / Mar.2020
Collapse of a Drill Pipe
M - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Ductile Behavior
Cm - Nital Etched Micrography by OMDf - Banded Structure
Micrography of the wheel in the center of the thickness, presenting a predominantly pearlitic structure and average hardness abot 196HB.
74
VIEW
ML00158 / Feb.2020
Surface Hardened Carbon Steel Wheel
M - High Carbon SteelP - WheelAp - TransportationCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Coarse Structure
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

More from these cases

ML00171 — Corrosion Fatigue of U Bolt Pipe ClampM - Low Carbon SteelP - BoltAp - ShipCd - Corrosion Fatigue
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
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
ML00162 — Valve Body Crack Growth from Weld DefectsM - Low Alloy Medium Carbon QTP - Valve BodyAp - O&G Well DrillingCd - Fatigue Induced by a Defect
Micrography of a longitudinal section of the valve body presenting a martensitic microstructure. The structure is banded and the darker regions show inclusions (grey sulfides).
50
VIEW
ML00162 / Apr.2020
Valve Body Crack Growth from Weld Defects
M - Low Alloy Medium Carbon QTP - Valve BodyAp - O&G Well DrillingCd - Fatigue Induced by a Defect
Cm - Nital Etched Micrography by OMDf - Martensite
Micrographic detail of the martensitic microstructure, in the longitudinal section. The hardness of the valve body is 34 HRc (Rockwell C) all through the thickness.
47
VIEW
ML00162 / Apr.2020
Valve Body Crack Growth from Weld Defects
M - Low Alloy Medium Carbon QTP - Valve BodyAp - O&G Well DrillingCd - Fatigue Induced by a Defect
Cm - Nital Etched Micrography by OMDf - Martensite
Micrography of the weld repair at the fusion line. Weld metal to the right and heat affected zone to the left.
37
VIEW
ML00162 / Apr.2020
Valve Body Crack Growth from Weld Defects
M - Low Alloy Medium Carbon QTP - Valve BodyAp - O&G Well DrillingCd - Fatigue Induced by a Defect
Cm - Nital Etched Micrography by OMDf - Fusion Line
Micrographic detail of the fusion line.
33
VIEW
ML00162 / Apr.2020
Valve Body Crack Growth from Weld Defects
M - Low Alloy Medium Carbon QTP - Valve BodyAp - O&G Well DrillingCd - Fatigue Induced by a Defect
Cm - Nital Etched Micrography by OMDf - Fusion Line
ML00161 — Brittle Fracture of a High Strength SocketM - Medium Carbon Tool SteelP - ToolAp - Oil and GasCd - Brittle Fracture
Micrography of a longitudinal section presenting an uniform tempered martensitic structure.
81
VIEW
ML00161 / Mar.2020
Brittle Fracture of a High Strength Socket
M - Medium Carbon Tool SteelP - ToolAp - Oil and GasCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Martensite
Micrographic detail of the tempered martensitic structure.
80
VIEW
ML00161 / Mar.2020
Brittle Fracture of a High Strength Socket
M - Medium Carbon Tool SteelP - ToolAp - Oil and GasCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Martensite
Brittle Fracture of a High Strength Socket
4
VIEW
ML00161 / Mar.2020
Brittle Fracture of a High Strength Socket
M - Medium Carbon Tool SteelP - ToolAp - Oil and GasCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Martensite
ML00159 — Collapse of a Drill PipeM - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Ductile Behavior
Micrographic detail of the tempered martensite in the longitudinal section of the pipe body. Uniform structure.
45
VIEW
ML00159 / Mar.2020
Collapse of a Drill Pipe
M - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Ductile Behavior
Cm - Nital Etched Micrography by OMDf - Martensite
Micrographic detail of the tempered martensite in the longitudinal section of the pipe body.
39
VIEW
ML00159 / Mar.2020
Collapse of a Drill Pipe
M - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Ductile Behavior
Cm - Nital Etched Micrography by OMDf - Martensite
Micrographic detail of sheared pipe, showing strong plastic deformation at the fracture. The structure shows the shear effect at the fracture.
16
VIEW
ML00159 / Mar.2020
Collapse of a Drill Pipe
M - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Ductile Behavior
Cm - Nital Etched Micrography by OMDf - Martensite
ML00158 — Surface Hardened Carbon Steel WheelM - High Carbon SteelP - WheelAp - TransportationCd - Removed From Service
Micrographic detail of the coarse pearlitic structure in the center of the wheel thickness. The part presents a wrought structure.
73
VIEW
ML00158 / Feb.2020
Surface Hardened Carbon Steel Wheel
M - High Carbon SteelP - WheelAp - TransportationCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Pearlite
Micrographic detail of the tempered martensitic structure.
50
VIEW
ML00158 / Feb.2020
Surface Hardened Carbon Steel Wheel
M - High Carbon SteelP - WheelAp - TransportationCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Martensite
Micrographic aspect of the pearlitic structure at the surface not heat treated, showing a lower grain size than in the center of the thickness.
35
VIEW
ML00158 / Feb.2020
Surface Hardened Carbon Steel Wheel
M - High Carbon SteelP - WheelAp - TransportationCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Pearlite
Micrographic detail of the pearlitic microstructure in a region where the structure is not so coarse than in the center of the thickness.
30
VIEW
ML00158 / Feb.2020
Surface Hardened Carbon Steel Wheel
M - High Carbon SteelP - WheelAp - TransportationCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Pearlite