Optical Microscope

13 cases · 91 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Product: Bolt clear all

Optical Microscope — sub-branches

As polished micrography 1Kalling Etched Micrography by OM 22Micrography by OM 9Micrography by OM using A262 Method A 12Nital Etched Micrography by OM 40Oxalic Acid Electrolytic Etch 7

Results

SortNewestOldestTitle A-ZTitle Z-A
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
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
Micrographic aspect of the rolled thread that was heat treated later. Longitudinal section.
134
VIEW
ML00130 / Jun.2018
Fatigue Fracture of Overloaded Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - O&G Well DrillingCd - Mechanical Fatigue
Cm - Nital Etched Micrography by OMDf - At the Surface
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
Micrographic detail of a longitudinal section in the center of the bolt. Granular austenitic microstructure, equiaxial, primary precipitates (isolated), precipitation hardened (not detectable by metalography, only because of the hardness level)
431
VIEW
ML00106 / Dec.2017
Inconel 718 Submarine Bolt
M - NiCrFe AlloyP - BoltAp - SubseaCd - Typical manufacturing
Cm - Kalling Etched Micrography by OMDf - Austenite
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
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

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 →

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 →

ML00130 — Fatigue Fracture of Overloaded BoltsM - Low Alloy Medium Carbon QTP - FastenerAp - O&G Well DrillingCd - Mechanical Fatigue
Micrographic aspect of the rolled thread that was heat treated later. Longitudinal section. The bolt was quenched and tempered to 30HRc and presented a martensitic structure.
124
VIEW
ML00130 / Jun.2018
Fatigue Fracture of Overloaded Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - O&G Well DrillingCd - Mechanical Fatigue
Cm - Nital Etched Micrography by OMDf - At the Surface
Micrographic detail of the rolled thread that was heat treated later. The bolt was quenched and tempered to 30 HRc and presented a martensitic structure.
110
VIEW
ML00130 / Jun.2018
Fatigue Fracture of Overloaded Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - O&G Well DrillingCd - Mechanical Fatigue
Cm - Nital Etched Micrography by OMDf - Martensite
The microstructure of the bolt is martensitic in the center of the thickness. Longitudinal section.
110
VIEW
ML00130 / Jun.2018
Fatigue Fracture of Overloaded Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - O&G Well DrillingCd - Mechanical Fatigue
Cm - Nital Etched Micrography by OMDf - In the Center of the Thickness
The microstructure of the bolt is martensitic in the center of the thickness. Longitudinal section.
103
VIEW
ML00130 / Jun.2018
Fatigue Fracture of Overloaded Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - O&G Well DrillingCd - Mechanical Fatigue
Cm - Nital Etched Micrography by OMDf - Martensite
Micrographic aspect of the rolled thread that was heat treated later. Longitudinal section.
115
VIEW
ML00130 / Jun.2018
Fatigue Fracture of Overloaded Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - O&G Well DrillingCd - Mechanical Fatigue
Cm - Nital Etched Micrography by OMDf - At the Surface

+3 more from this case →

ML00120 — Ductile Rupture of a Carbon Steel Eye BoltM - Low Carbon SteelP - FastenerAp - AutomotiveCd - Overload
Micrography of a longitudinal section of the bolt in the center of the thickness, presenting a ferritic pearlitic structure with elongated grains due to the forming process, without later heat treatment.
173
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 - Ferrite and Pearlite
Micrographic detail of the ferritic pearlitic structure, with grains sligthly elongated.
156
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 - Ferrite and Pearlite
Micrography of a longitudinal section of the bolt at the bottom of the thread fillet, presenting a plastically deformed ferritic pearlitic structure in a very small extension from the surface (about 0.1mm). This analysis was conducted in a position far from the failure and the structure was created by the cold forming process to manufacture the thread.
151
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 - Rolled Thread
Micrographic detail of a longitudinal section of the bolt at the bottom of the thread fillet, presenting a plastically deformed ferritic pearlitic structure. This analysis was conducted far from the failure and the structure was created by the cold forming process to manufacture the thread.
147
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 - Strain Hardened
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

+1 more from this case →

ML00106 — Inconel 718 Submarine BoltM - NiCrFe AlloyP - BoltAp - SubseaCd - Typical manufacturing
Micrography of a longitudinal section in the center of the bolt. Granular austenitic microstructure, equiaxial, primary precipitates (isolated), precipitation hardened (not detectable by metalography, only because of the hardness level)
63
VIEW
ML00106 / Dec.2017
Inconel 718 Submarine Bolt
M - NiCrFe AlloyP - BoltAp - SubseaCd - Typical manufacturing
Cm - Kalling Etched Micrography by OMDf - Longitudinal Section
Low magnification micrography of the bolt in a longitudinal section, at the bolt thread, showing no evidences of forming operations, indicating that it was machined from a heat treated bar. Austenitic microstructure, granular, equiaxial.
54
VIEW
ML00106 / Dec.2017
Inconel 718 Submarine Bolt
M - NiCrFe AlloyP - BoltAp - SubseaCd - Typical manufacturing
Cm - Kalling Etched Micrography by OMDf - Longitudinal Section
Micrography of the bolt in a longitudinal section, at the bolt thread, showing no evidences of forming operations, indicating that it was machined from a heat treated bar. Austenitic microstructure, granular, equiaxial.
49
VIEW
ML00106 / Dec.2017
Inconel 718 Submarine Bolt
M - NiCrFe AlloyP - BoltAp - SubseaCd - Typical manufacturing
Cm - Kalling Etched Micrography by OMDf - Machined Thread
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 →

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