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

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Low magnification micrography of the bolt in a longitudinal section, at the bolt thread, showing no evidences of forming operations, indicating it was machined from a heat treated bar. Austenitic microstructure, granular, equiaxial, precipitation hardened (shadow in the grains).
45
VIEW
ML00105 / Jun.2018
Inconel 718 Bolt of Special Head
M - NiCrFe AlloyP - FastenerAp - SubseaCd - Typical manufacturing
Cm - Kalling Etched Micrography by OMDf - Longitudinal Section
The micrography of the longitudinal section of the tube, close to OD, shows the paralel cracks, filled with oxides, perpendicular to the surface.
1441
VIEW
ML00104 / Dec.2017
Thermal Fatigue of a Boiler Tube
M - Low Carbon SteelP - Autogenously Welded TubeAp - BoilerCd - Thermal Fatigue
Cm - As polished micrographyDf - Close to the External Surface
Micrography of the longitudinal section of the fitiing, in a free-cutting steel. The microstructure is predominantly ferritic and there is a large amount of sulfide inclusions, aligned perpendicular to the forming direction.
97
VIEW
ML00103 / Nov.2017
Brittle Fracture of a Free-Cutting Connector
M - Low Carbon SteelP - Machined PartAp - ShipCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Longitudinal Section
Micrography of the 4130 steel, normalized and tempered. The structure is sligthly banded (segregated) and the average hardness level is 20 HRc.
92
VIEW
ML00102 / May.2018
AISI 4130 Forging Welded and Overlaid
M - Low Alloy SteelP - CladdingAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Base Metal
Micrographic detail of the strain hardened austenitic structure in the longitudinal section of the bolt.
441
VIEW
ML00101 / Nov.2017
High Strength 316SS Bolt
M - Austenitic Stainless SteelP - BoltAp - SubseaCd - Typical manufacturing
Cm - Micrography by OM using A262 Method ADf - Austenite
Micrographic detail of the strain hardened austenitic structure in the longitudinal section of the bolt.
412
VIEW
ML00087 / Nov.2017
High Strength Austenitic SS Bolt
M - Austenitic Stainless SteelP - BoltAp - SubseaCd - Typical manufacturing
Cm - Micrography by OM using A262 Method ADf - 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 pin microstructure at the longitudinal section showing a tempered martensitic structure and a band of retained austenite.
60
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Kalling Etched Micrography by OMDf - Martensite

More from these cases

ML00105 — Inconel 718 Bolt of Special HeadM - NiCrFe AlloyP - FastenerAp - SubseaCd - Typical manufacturing
Micrography of the bolt in a longitudinal section, at the bolt thread, showing no evidences of forming operations, indicating it was machined from a heat treated bar. Austenitic microstructure, granular, equiaxial, precipitation hardened (shadow in the grains).
39
VIEW
ML00105 / Jun.2018
Inconel 718 Bolt of Special Head
M - NiCrFe AlloyP - FastenerAp - SubseaCd - Typical manufacturing
Cm - Kalling Etched Micrography by OMDf - Machined Thread
Micrographic detail of the bolt in a longitudinal section, at the bolt thread, showing no evidences of forming operations, indicating it was machined from a heat treated bar. Austenitic microstructure, granular, equiaxial, precipitation hardened (shadow in the grains).
31
VIEW
ML00105 / Jun.2018
Inconel 718 Bolt of Special Head
M - NiCrFe AlloyP - FastenerAp - SubseaCd - Typical manufacturing
Cm - Kalling Etched Micrography by OMDf - Machined Thread
Low magnification micrography of the bolt in a longitudinal section, at the bolt head, showing no evidences of forming operations, indicating it was machined from a heat treated bar. Austenitic microstructure, granular, equiaxial, precipitation hardened (shadow in the grains).
31
VIEW
ML00105 / Jun.2018
Inconel 718 Bolt of Special Head
M - NiCrFe AlloyP - FastenerAp - SubseaCd - Typical manufacturing
Cm - Kalling Etched Micrography by OMDf - Longitudinal Section
Micrography of the bolt in a longitudinal section, at the bolt head, showing no evidences of forming operations, indicating it was machined from a heat treated bar. Austenitic microstructure, granular, equiaxial, precipitation hardened (shadow in the grains).
31
VIEW
ML00105 / Jun.2018
Inconel 718 Bolt of Special Head
M - NiCrFe AlloyP - FastenerAp - SubseaCd - Typical manufacturing
Cm - Kalling Etched Micrography by OMDf - Austenite
Micrographic detail of the bolt in a longitudinal section, at the bolt head, showing no evidences of forming operations, indicating it was machined from a heat treated bar. Austenitic microstructure, granular, equiaxial, precipitation hardened (shadow in the grains).
26
VIEW
ML00105 / Jun.2018
Inconel 718 Bolt of Special Head
M - NiCrFe AlloyP - FastenerAp - SubseaCd - Typical manufacturing
Cm - Kalling Etched Micrography by OMDf - Equiaxial Grains

+3 more from this case →

ML00104 — Thermal Fatigue of a Boiler TubeM - Low Carbon SteelP - Autogenously Welded TubeAp - BoilerCd - Thermal Fatigue
The micrography of the longitudinal section of the tube, close to ID, shows the paralel cracks, filled with oxides, perpendicular to the surface.
229
VIEW
ML00104 / Dec.2017
Thermal Fatigue of a Boiler Tube
M - Low Carbon SteelP - Autogenously Welded TubeAp - BoilerCd - Thermal Fatigue
Cm - As polished micrographyDf - Close to the Internal Surface
Micrographic details of the longitudinal section of the tube, close to OD, showing paralel cracks, filled with oxides, perpendicular to the surface.
115
VIEW
ML00104 / Dec.2017
Thermal Fatigue of a Boiler Tube
M - Low Carbon SteelP - Autogenously Welded TubeAp - BoilerCd - Thermal Fatigue
Cm - As polished micrographyDf - Cracks Transverse to the Surface
Micrographic details of the longitudinal section of the tube, close to OD, showing paralel cracks, filled with oxides, perpendicular to the surface.
109
VIEW
ML00104 / Dec.2017
Thermal Fatigue of a Boiler Tube
M - Low Carbon SteelP - Autogenously Welded TubeAp - BoilerCd - Thermal Fatigue
Cm - As polished micrographyDf - Thermal Fatigue Cracks
Micrographic details of the longitudinal section of the tube, close to ID, showing paralel cracks, filled with oxides, perpendicular to the surface.
103
VIEW
ML00104 / Dec.2017
Thermal Fatigue of a Boiler Tube
M - Low Carbon SteelP - Autogenously Welded TubeAp - BoilerCd - Thermal Fatigue
Cm - As polished micrographyDf - Cracks Transverse to the Surface
Micrographic details of the longitudinal section of the tube, close to ID, showing paralel cracks, filled with oxides, perpendicular to the surface.
99
VIEW
ML00104 / Dec.2017
Thermal Fatigue of a Boiler Tube
M - Low Carbon SteelP - Autogenously Welded TubeAp - BoilerCd - Thermal Fatigue
Cm - As polished micrographyDf - Thermal Fatigue Cracks

+10 more from this case →

ML00103 — Brittle Fracture of a Free-Cutting ConnectorM - Low Carbon SteelP - Machined PartAp - ShipCd - Brittle Fracture
Micrographic detail of the longitudinal section of the fitiing, in a free-cutting steel. The microstructure is predominantly ferritic, with small perlitic areas and some free cementite at ferritic grain boundaries. There is a large amount of sulfide inclusions, aligned perpendicular to the forming direction.
106
VIEW
ML00103 / Nov.2017
Brittle Fracture of a Free-Cutting Connector
M - Low Carbon SteelP - Machined PartAp - ShipCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Non Metallic Inclusions
Micrography of the transerse section of the fitiing, in a free-cutting steel. The microstructure is predominantly ferritic and the inclusions appear as dots.
96
VIEW
ML00103 / Nov.2017
Brittle Fracture of a Free-Cutting Connector
M - Low Carbon SteelP - Machined PartAp - ShipCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Transverse Section
Micrographic detail of the transverse section of the fitiing, in a free-cutting steel. The microstructure is predominantly ferritic, some perlitic areas and free cementite at ferritic grain boundaries. There is a large amount of inclusions, that appear as spots.
82
VIEW
ML00103 / Nov.2017
Brittle Fracture of a Free-Cutting Connector
M - Low Carbon SteelP - Machined PartAp - ShipCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Predominantly Ferritic
The longitudinal section of the fitting at the thread shows plastic deformation of the fillets, and a crack at the bottom of the thread.
56
VIEW
ML00103 / Nov.2017
Brittle Fracture of a Free-Cutting Connector
M - Low Carbon SteelP - Machined PartAp - ShipCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Crack
Micrographic detail of the longitudinal section of the fitting at the thread, showing a crack at the bottom of the thread.
53
VIEW
ML00103 / Nov.2017
Brittle Fracture of a Free-Cutting Connector
M - Low Carbon SteelP - Machined PartAp - ShipCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Crack

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ML00102 — AISI 4130 Forging Welded and OverlaidM - Low Alloy SteelP - CladdingAp - Oil and GasCd - Welding
Micrography of the 4130 steel, normalized and tempered. The microstructure is bainitic.
88
VIEW
ML00102 / May.2018
AISI 4130 Forging Welded and Overlaid
M - Low Alloy SteelP - CladdingAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Base Metal
Micrographic detail of the bainitic structure of the 4130 steel, normalized and tempered.
87
VIEW
ML00102 / May.2018
AISI 4130 Forging Welded and Overlaid
M - Low Alloy SteelP - CladdingAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Bainite
Micrography of the tubular 4130 forging at the heat affected zone (HAZ) of the Inconel overlay (white because it was not etched with the Nital). The structure is ferritic/bainitic because the overlay was conducted in two layers, and all the HAZ was reheated during welding.
66
VIEW
ML00102 / May.2018
AISI 4130 Forging Welded and Overlaid
M - Low Alloy SteelP - CladdingAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Heat Affected Zone
Micrography of the tubular 4130 forging at the heat affected zone (HAZ) of the Inconel overlay (white because it was not etched with the Nital). The structure is ferritic/bainitic because the overlay was conducted in two layers, and all the HAZ was reheated during welding.
61
VIEW
ML00102 / May.2018
AISI 4130 Forging Welded and Overlaid
M - Low Alloy SteelP - CladdingAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Heat Affected Zone
Micrographic detail of the bainitic heat affected zone (HAZ) of 4130 forging at the Inconel overlay.
50
VIEW
ML00102 / May.2018
AISI 4130 Forging Welded and Overlaid
M - Low Alloy SteelP - CladdingAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Bainitic Ferrite

+6 more from this case →

ML00101 — High Strength 316SS BoltM - Austenitic Stainless SteelP - BoltAp - SubseaCd - Typical manufacturing
Micrography of the longitudinal section of the bolt, in the center of the body thickness. Strain hardened austenic structure.
52
VIEW
ML00101 / Nov.2017
High Strength 316SS Bolt
M - Austenitic Stainless SteelP - BoltAp - SubseaCd - Typical manufacturing
Cm - Micrography by OM using A262 Method ADf - Strain Hardened
Micrography of the longitudinal section of the bolt, in the center of the body thickness. Strain hardened austenic structure.
46
VIEW
ML00101 / Nov.2017
High Strength 316SS Bolt
M - Austenitic Stainless SteelP - BoltAp - SubseaCd - Typical manufacturing
Cm - Micrography by OM using A262 Method ADf - Strain Hardened
Micrography of the longitudinal section of the bolt, at the thread. The bolt was cold deformed and the thread was cold rolled.
32
VIEW
ML00101 / Nov.2017
High Strength 316SS Bolt
M - Austenitic Stainless SteelP - BoltAp - SubseaCd - Typical manufacturing
Cm - Micrography by OM using A262 Method ADf - Strain Hardened
Micrography of the longitudinal section of the bolt, at the thread. The bolt was cold deformed and the thread was cold rolled.
31
VIEW
ML00101 / Nov.2017
High Strength 316SS Bolt
M - Austenitic Stainless SteelP - BoltAp - SubseaCd - Typical manufacturing
Cm - Micrography by OM using A262 Method ADf - Strain Hardened
Micrographic detail of the strain hardened austenitic structure at the thread.
25
VIEW
ML00101 / Nov.2017
High Strength 316SS Bolt
M - Austenitic Stainless SteelP - BoltAp - SubseaCd - Typical manufacturing
Cm - Micrography by OM using A262 Method ADf - Austenite
ML00087 — High Strength Austenitic SS BoltM - Austenitic Stainless SteelP - BoltAp - SubseaCd - Typical manufacturing
Micrography of the longitudinal section of the bolt, in the center of the body thickness. Strain hardened austenic structure.
73
VIEW
ML00087 / Nov.2017
High Strength Austenitic SS Bolt
M - Austenitic Stainless SteelP - BoltAp - SubseaCd - Typical manufacturing
Cm - Micrography by OM using A262 Method ADf - Strain Hardened
Micrography of the longitudinal section of the bolt, in the center of the body thickness. Strain hardened austenic structure.
62
VIEW
ML00087 / Nov.2017
High Strength Austenitic SS Bolt
M - Austenitic Stainless SteelP - BoltAp - SubseaCd - Typical manufacturing
Cm - Micrography by OM using A262 Method ADf - Strain Hardened
Micrography of the longitudinal section of the bolt, at the thread. The bolt was cold deformed and the thread was cold rolled.
65
VIEW
ML00087 / Nov.2017
High Strength Austenitic SS Bolt
M - Austenitic Stainless SteelP - BoltAp - SubseaCd - Typical manufacturing
Cm - Micrography by OM using A262 Method ADf - Strain Hardened
Micrography of the longitudinal section of the bolt, at the thread. The bolt was cold deformed and the thread was cold rolled.
65
VIEW
ML00087 / Nov.2017
High Strength Austenitic SS Bolt
M - Austenitic Stainless SteelP - BoltAp - SubseaCd - Typical manufacturing
Cm - Micrography by OM using A262 Method ADf - Strain Hardened
Micrographic detail of the strain hardened austenitic structure at the thread.
59
VIEW
ML00087 / Nov.2017
High Strength Austenitic SS Bolt
M - Austenitic Stainless SteelP - BoltAp - SubseaCd - Typical manufacturing
Cm - Micrography by OM using A262 Method ADf - Austenite
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 →

ML00085 — Corrosion Fatigue of a Martensitic SS PinM - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Micrographic detail of the pin microstructure at the longitudinal section showing a tempered martensitic structure and a band of retained austenite.
61
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Kalling Etched Micrography by OMDf - Banded Structure
Micrographic detail of the pin microstructure at the longitudinal section showing a band of retained austenite in martensitic structure.
58
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Kalling Etched Micrography by OMDf - Martensite
Micrography of the pin in a longitudinal section, transverse to the fracture surface, close to the point of cracking iniciation, presenting a flat propagation and a secondary crack, paralel to the fracture surface.
54
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Kalling Etched Micrography by OMDf - Fracture
Micrography of the pin in a longitudinal section, transverse to the fracture surface, close to the point of cracking iniciation, presenting a flat propagation and a secondary crack, paralel to the fracture surface.
52
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Kalling Etched Micrography by OMDf - Fracture
Micrographic detail of a secondary cracking close to the fracture position. The crack presents no plastic deformation, is slightly branched and filled with products.
52
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Kalling Etched Micrography by OMDf - Fatigue Fracture

+6 more from this case →