Optical Microscope

8 cases · 47 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Microstructure: Strain Hardened Detail focus: Damage clear all

Optical Microscope — sub-branches

As polished micrography 4Kalling Etched Micrography by OM 1Keller Etched Micrography by OM 11Micrography by OM using A262 Method A 2Nital Etched Micrography by OM 22Oxalic Acid Electrolytic Etch 7

Results

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Metallographic detail of the wire surface in one strand external wire, showing the presence of oxides.
39
VIEW
ML00175 / Aug.2021
Localized External Wear of a Wire Rope
M - High Carbon SteelP - Wire RopeAp - Oil and GasCd - Wear
Cm - Nital Etched Micrography by OMDf - Oxide Layer
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 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 the damaged plate at the side of the bullet impact, top of the figure. The perforated hole expulsed the material to the top and bottom directions and the microstructure shows plastic deformation.
16
VIEW
ML00145 / Sep.2018
Impact of a .380 Winchester on 6061 T6 Plate
M - Aluminum Magnesium SiliconP - Rolled PlateAp - StructureCd - Pierced
Cm - Keller Etched Micrography by OMDf - Plastic Deformation
Micrographic detail of the plate section, as polished, close to the surface that suffered the impact. The copper alloy melted and created a yellow-orange deposit.
25
VIEW
ML00143 / Aug.2018
Impact of a .308 Winchester on A36 Plate
M - Low Carbon SteelP - Rolled PlateAp - StructureCd - Pierced
Cm - As polished micrographyDf - Melted film
Micrographic detail of the damaged region close to the external surface, presenting a shallow localized dissolution/corrosion.
48
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 - Localized Corrosion
Micrography as polished of the longitudinal section of the bolt at the fracture position. The fracture (top of the figure) is rough, characteristic of a ductile fracture.
196
VIEW
ML00120 / Jun.2018
Ductile Rupture of a Carbon Steel Eye Bolt
M - Low Carbon SteelP - FastenerAp - AutomotiveCd - Overload
Cm - As polished micrographyDf - Fracture
Micrography of a longitudinal section of the wire, at the fracture surface (top of the figure) evidencing the intergranular and transgranular aspects of the hydrogen assisted cracking mechanism.
37
VIEW
ML00076 / Jun.2017
Hydrogen Cracking of a 17-7 PH Subsea Spring
M - Precipitation Hardened Stainless SteelP - WireAp - SubseaCd - Hydrogen Embrittlement
Cm - Micrography by OM using A262 Method ADf - Secondary Cracks

More from these cases

ML00157 — Bolts Under Chloride SCC ConditionsM - Austenitic Stainless SteelP - BoltAp - Oil and GasCd - Stress Corrosion
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
Detailed aspect of the stress corrosion cracks in a longitudinal section of the fractured bolt, under the thread. The microstructure is strain hardened austenite.
47
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
Detailed aspect of the brached transgranular stress corrosion cracks, in a longitudinal section of the fractured bolt. The microstructure is strain hardened austenite.
40
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
ML00155 — Failure of a Prestressed Concrete Steel StrandM - High Carbon SteelP - Wire RopeAp - StructureCd - Corrosion Fatigue
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
Failure of a Prestressed Concrete Steel Strand
5
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
ML00145 — Impact of a .380 Winchester on 6061 T6 PlateM - Aluminum Magnesium SiliconP - Rolled PlateAp - StructureCd - Pierced
Micrographic detail of the plastically deformed microstructure at the side of the bullet impact, top of the figure. The perforated hole expulsed the material to the top and bottom directions.
16
VIEW
ML00145 / Sep.2018
Impact of a .380 Winchester on 6061 T6 Plate
M - Aluminum Magnesium SiliconP - Rolled PlateAp - StructureCd - Pierced
Cm - Keller Etched Micrography by OMDf - Plastic Deformation
Micrography of the damaged plate close to the perforated hole, in the middle of the thickness, showing the strong plastic deformation of the structure.
12
VIEW
ML00145 / Sep.2018
Impact of a .380 Winchester on 6061 T6 Plate
M - Aluminum Magnesium SiliconP - Rolled PlateAp - StructureCd - Pierced
Cm - Keller Etched Micrography by OMDf - Plastic Deformation
Micrography of the damaged plate close to the perforated hole, in the middle of the thickness, showing the strong plastic deformation of the structure and ductile secondary cracks.
10
VIEW
ML00145 / Sep.2018
Impact of a .380 Winchester on 6061 T6 Plate
M - Aluminum Magnesium SiliconP - Rolled PlateAp - StructureCd - Pierced
Cm - Keller Etched Micrography by OMDf - Ductile Fracture
Micrograpic detail of the secondary ductile cracks.
13
VIEW
ML00145 / Sep.2018
Impact of a .380 Winchester on 6061 T6 Plate
M - Aluminum Magnesium SiliconP - Rolled PlateAp - StructureCd - Pierced
Cm - Keller Etched Micrography by OMDf - Ductile Crack
Micrography of the damaged plate close to the perforated hole, in the middle of the thickness, showing the strong plastic deformation of the structure, with the grains changing its direction to transverse to the thickness.
6
VIEW
ML00145 / Sep.2018
Impact of a .380 Winchester on 6061 T6 Plate
M - Aluminum Magnesium SiliconP - Rolled PlateAp - StructureCd - Pierced
Cm - Keller Etched Micrography by OMDf - Plastic Deformation

+5 more from this case →

ML00143 — Impact of a .308 Winchester on A36 PlateM - Low Carbon SteelP - Rolled PlateAp - StructureCd - Pierced
Micrographic detail of the plate section, as polished, close to the surface that suffered the impact. The copper alloy melted and created a yellow-orange deposit.
26
VIEW
ML00143 / Aug.2018
Impact of a .308 Winchester on A36 Plate
M - Low Carbon SteelP - Rolled PlateAp - StructureCd - Pierced
Cm - As polished micrographyDf - Melted film
Micrography of the plate section, close to the surface that suffered the impact. The copper alloy melted and created a yellow-orange deposit. The plate material presented a strong plastic deformation, aligning the grains and strain hardening the microstructure.
26
VIEW
ML00143 / Aug.2018
Impact of a .308 Winchester on A36 Plate
M - Low Carbon SteelP - Rolled PlateAp - StructureCd - Pierced
Cm - Nital Etched Micrography by OMDf - Plastic Deformation
Micrographic detail of the copper alloy melted and adhered at the surface and a strong plastic deformation of the plate microstructure.
28
VIEW
ML00143 / Aug.2018
Impact of a .308 Winchester on A36 Plate
M - Low Carbon SteelP - Rolled PlateAp - StructureCd - Pierced
Cm - Nital Etched Micrography by OMDf - Plastic Deformation
Micrography of the damaged plate at the side of the bullet impact, top of the figure. The perforated hole expulsed the material to the top and bottom directions and the copper alloy is evident at the hole surface.After etching it is clear the strong plastic deformation of the plate microstructure.
25
VIEW
ML00143 / Aug.2018
Impact of a .308 Winchester on A36 Plate
M - Low Carbon SteelP - Rolled PlateAp - StructureCd - Pierced
Cm - Nital Etched Micrography by OMDf - Plastic Deformation
Micrographic detail of the damaged plate at the side of the bullet impact. The perforated hole expulsed the material to the top and bottom directions and the copper alloy is evident at the hole surface. There is a strong plastic deformation of the ferritic-pearlitic microstructure and the hardness level increased from 151 HV to 308 HV (1kg).
19
VIEW
ML00143 / Aug.2018
Impact of a .308 Winchester on A36 Plate
M - Low Carbon SteelP - Rolled PlateAp - StructureCd - Pierced
Cm - Nital Etched Micrography by OMDf - Plastic Deformation

+11 more from this case →

ML00135 — MIC of a Non Magnetic Drilling ToolM - High Mn Austenitic SteelP - Tubular ForgingAp - O&G Well DrillingCd - Pitting Corrosion
Micrography of the damaged region close to the internal surface, presenting a deep pitting corrosion morphology.
40
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 - Localized Corrosion
ML00120 — Ductile Rupture of a Carbon Steel Eye BoltM - Low Carbon SteelP - FastenerAp - AutomotiveCd - Overload
Micrography of a longitudinal section of the bolt at the thread fillet adjacent to the fracture, presenting a ductile cracking from the bottom of the fillet, propagating with a strong plastic deformation. The deformation lines of the cold formed process (thread cold rolling) are also deformed by the cracking propagation.
141
VIEW
ML00120 / Jun.2018
Ductile Rupture of a Carbon Steel Eye Bolt
M - Low Carbon SteelP - FastenerAp - AutomotiveCd - Overload
Cm - Nital Etched Micrography by OMDf - Ductile Crack
Micrographic detail of a longitudinal section of the bolt at the bottom of the thread fillet adjacent to the fracture, presenting a ductile cracking propagating with a plastic deformation. The deformation lines of the cold formed process are also deformed by the cracking propagation and there are some other small secondary cracks at 90° from the principal cracking.
133
VIEW
ML00120 / Jun.2018
Ductile Rupture of a Carbon Steel Eye Bolt
M - Low Carbon SteelP - FastenerAp - AutomotiveCd - Overload
Cm - Nital Etched Micrography by OMDf - Ductile Crack
ML00076 — Hydrogen Cracking of a 17-7 PH Subsea SpringM - Precipitation Hardened Stainless SteelP - WireAp - SubseaCd - Hydrogen Embrittlement
Micrographic detail of a longitudinal section of the wire, at the fracture surface (top of the figure) evidencing the intergranular and transgranular aspects of the hydrogen assisted cracking mechanism. The electrolytic oxalic acid etch reveals the delta ferrite phase. Compare with the Kalling etch in the other figure.
31
VIEW
ML00076 / Jun.2017
Hydrogen Cracking of a 17-7 PH Subsea Spring
M - Precipitation Hardened Stainless SteelP - WireAp - SubseaCd - Hydrogen Embrittlement
Cm - Micrography by OM using A262 Method ADf - Fracture
Micrographic detail of a longitudinal section of the wire, at the fracture surface (top of the figure) evidencing the intergranular and transgranular aspects of the hydrogen assisted cracking mechanism. The Kalling etch does not reveal the delta ferrite. Compare with the electrolytic oxalic acid etch in the other figure.
29
VIEW
ML00076 / Jun.2017
Hydrogen Cracking of a 17-7 PH Subsea Spring
M - Precipitation Hardened Stainless SteelP - WireAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Fracture