Kalling Etched Micrography by OM

10 cases · 79 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

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Micrography of a longitudinal section, in the center, of the broken 5/8" bolt, presenting an aged martensitic structure. There are vertical "lines" that correspond to segregation bands due to the forming direction. These bands are evident only using low magnification microscopy.
168
VIEW
ML00139 / Jun.2018
Hydrogen Fracture of a 17-4 PH Allen Bolt
M - Precipitation Hardened Stainless SteelP - Allen BoltAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Longitudinal Section
17-4 PH rod. Micrography of the longitudinal section in the center of the thickness, presenting an aged martensitic structure. The darker lines are bands of (sligthly) segregated regions. This material presents properties that correspond to the H1150 grade.
73
VIEW
ML00121 / Feb.2018
Pitting Corrosion in a Subsea System
M - Austenitic / MartensiticP - Rod & CylinderAp - SubseaCd - Pitting Corrosion
Cm - Kalling Etched Micrography by OMDf - Martensite
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 austenitic structure at the surface, where the grain size of the material increased. By optical microscopy the intragranular precipitation due to solution annealing and aging is not revealed.
794
VIEW
ML00089 / Sep.2017
Inconel 718 Allen Bolt for Subsea Application
M - NiCrFe AlloyP - Machined PartAp - SubseaCd - Typical manufacturing
Cm - Kalling Etched Micrography by OMDf - Austenite
Micrography of the longitudinal section of the forging material, presenting a granular austenite, precipitation hardened.
84
VIEW
ML00078 / Jun.2017
Hydrogen Cracking of IN 718 Subsea Connector
M - NiCrFe AlloyP - ForgingAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Longitudinal Section
The longitudinal section of the spring wire shows a strain hardened martensitic structure, aged to high strength (602 HV 0.3kg). Previous austenite grains are elongated.
55
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 - Longitudinal Section
The stud presents an austenitic structure, with primary and secondary precipitates of a size that is visible in low magnification microscopy.
55
VIEW
ML00075 / Jun.2018
Hydrogen Cracking of IN 718 Subsea Fasteners
M - NiCrFe AlloyP - StudAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Austenite

More from these cases

ML00139 — Hydrogen Fracture of a 17-4 PH Allen BoltM - Precipitation Hardened Stainless SteelP - Allen BoltAp - SubseaCd - Hydrogen Embrittlement
Micrography of a longitudinal section, in the center, of the broken 5/8" bolt, presenting an aged martensitic structure.
133
VIEW
ML00139 / Jun.2018
Hydrogen Fracture of a 17-4 PH Allen Bolt
M - Precipitation Hardened Stainless SteelP - Allen BoltAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Martensite
Micrographic detail of the aged martensitic structure. The bolt presented variations in the previous austenite grain boundaries from the center of the thickness to the surface. No delta ferrite or retained austenite islands are evidenced.
107
VIEW
ML00139 / Jun.2018
Hydrogen Fracture of a 17-4 PH Allen Bolt
M - Precipitation Hardened Stainless SteelP - Allen BoltAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Martensite
Micrography of a longitudinal section of the 5/8" bolt, at the bottom of the thread, presenting a refined structure compared to the center of the bolt and a mark at the thread flank that was probably created during tightening of the bolt.
95
VIEW
ML00139 / Jun.2018
Hydrogen Fracture of a 17-4 PH Allen Bolt
M - Precipitation Hardened Stainless SteelP - Allen BoltAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Longitudinal Section
Micrography of a longitudinal section of the 5/8" bolt, at the bottom of the thread, presenting a refined structure compared to the center of the bolt. The structure is aged martensite.
91
VIEW
ML00139 / Jun.2018
Hydrogen Fracture of a 17-4 PH Allen Bolt
M - Precipitation Hardened Stainless SteelP - Allen BoltAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Martensite
Micrographic detail of the aged martensite structure, refined when compared to the structure in the center of the bolt.
87
VIEW
ML00139 / Jun.2018
Hydrogen Fracture of a 17-4 PH Allen Bolt
M - Precipitation Hardened Stainless SteelP - Allen BoltAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Martensite

+16 more from this case →

ML00121 — Pitting Corrosion in a Subsea SystemM - Austenitic / MartensiticP - Rod & CylinderAp - SubseaCd - Pitting Corrosion
17-4 PH rod. Micrography of the longitudinal section in the center of the thickness, presenting an aged martensitic structure. The darker lines are bands of (sligthly) segregated regions. This material presents properties that correspond to the H1150 grade.
66
VIEW
ML00121 / Feb.2018
Pitting Corrosion in a Subsea System
M - Austenitic / MartensiticP - Rod & CylinderAp - SubseaCd - Pitting Corrosion
Cm - Kalling Etched Micrography by OMDf - Martensite
17-4 PH rod. Micrographic detail of the aged martensitic structure. At this magnification level the previous austenite grain boundaries are evidenced. It is also possible to see that the bands of (sligthly) segregated regions are all martensitic.
64
VIEW
ML00121 / Feb.2018
Pitting Corrosion in a Subsea System
M - Austenitic / MartensiticP - Rod & CylinderAp - SubseaCd - Pitting Corrosion
Cm - Kalling Etched Micrography by OMDf - Martensite
17-4 PH rod. Micrography of the longitudinal section close to the surface, presenting the roughness (the waves at the surface) and a region where a pitting was still in the beginning, not related to any specific microstructure.
70
VIEW
ML00121 / Feb.2018
Pitting Corrosion in a Subsea System
M - Austenitic / MartensiticP - Rod & CylinderAp - SubseaCd - Pitting Corrosion
Cm - Kalling Etched Micrography by OMDf - Pitting
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 →

ML00089 — Inconel 718 Allen Bolt for Subsea ApplicationM - NiCrFe AlloyP - Machined PartAp - SubseaCd - Typical manufacturing
The micrography of a longitudinal section of the bolt close to the surface, at the thread, shows that it was machined from a bar, not rolled.
37
VIEW
ML00089 / Sep.2017
Inconel 718 Allen Bolt for Subsea Application
M - NiCrFe AlloyP - Machined PartAp - SubseaCd - Typical manufacturing
Cm - Kalling Etched Micrography by OMDf - Machined Thread
The micrography of a longitudinal section of the bolt, in the center of the thickness (ND 1/2"), shows an equiaxial granular structure. Although the material was hardened by heat treatment (solution annealing and aging), the microstructure at this magnification does not reveal the intragranular precipitation.
34
VIEW
ML00089 / Sep.2017
Inconel 718 Allen Bolt for Subsea Application
M - NiCrFe AlloyP - Machined PartAp - SubseaCd - Typical manufacturing
Cm - Kalling Etched Micrography by OMDf - Equiaxial Grains
Micrographic detail of a longitudinal section of the bolt, close to the surface (ND 1/2"). The grain size is higher than the center of the bolt.
27
VIEW
ML00089 / Sep.2017
Inconel 718 Allen Bolt for Subsea Application
M - NiCrFe AlloyP - Machined PartAp - SubseaCd - Typical manufacturing
Cm - Kalling Etched Micrography by OMDf - Austenite
ML00078 — Hydrogen Cracking of IN 718 Subsea ConnectorM - NiCrFe AlloyP - ForgingAp - SubseaCd - Hydrogen Embrittlement
Micrography of the longitudinal section of the conector, at the fracture position, showing secondary cracks from the fracture surface.
63
VIEW
ML00078 / Jun.2017
Hydrogen Cracking of IN 718 Subsea Connector
M - NiCrFe AlloyP - ForgingAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Fracture
The micrographic detail of the longitudinal section at the fracture surface shows intergranular morphology for the secondary cracks (longitudinal to the forging axis).
64
VIEW
ML00078 / Jun.2017
Hydrogen Cracking of IN 718 Subsea Connector
M - NiCrFe AlloyP - ForgingAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Secondary Cracks
Micrographic detail of a longitudinal section of the connector, at the fracture surface (in the top), showing intergranular secondary cracks.
54
VIEW
ML00078 / Jun.2017
Hydrogen Cracking of IN 718 Subsea Connector
M - NiCrFe AlloyP - ForgingAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Intergranular Cracking
Micrographic detail of a longitudinal section of the connector, at the fracture surface (in the top), showing intergranular secondary cracks. There is a large amount of delta phase precipitated intergranular and intragranluar.
48
VIEW
ML00078 / Jun.2017
Hydrogen Cracking of IN 718 Subsea Connector
M - NiCrFe AlloyP - ForgingAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Secondary Cracks
ML00076 — Hydrogen Cracking of a 17-7 PH Subsea SpringM - Precipitation Hardened Stainless SteelP - WireAp - SubseaCd - Hydrogen Embrittlement
Micrographic detail of the strain hardened aged martensitic structure. Small aligned delta ferrite islands can be seen.
51
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 - Longitudinal Section
The transverse section of the spring wire shows a strain hardened martensitic structure, aged to high strength (602 HV 0.3kg).
48
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 - Transverse Section
Micrographic detail of the strain hardened aged martensitic structure.
48
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 - Transverse Section
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
Micrographic detail of the spring wire surface, far from the fracture, showing several small intergranular cracks.
40
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 - At the Surface
ML00075 — Hydrogen Cracking of IN 718 Subsea FastenersM - NiCrFe AlloyP - StudAp - SubseaCd - Hydrogen Embrittlement
The stud structure evidences grain boundaries precipitation of probably delta phase (an overaging of the hardening precipitate).
49
VIEW
ML00075 / Jun.2018
Hydrogen Cracking of IN 718 Subsea Fasteners
M - NiCrFe AlloyP - StudAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Austenite
Micrography of a longitudinal section of the stud, at the fracture surface, in the thread.
44
VIEW
ML00075 / Jun.2018
Hydrogen Cracking of IN 718 Subsea Fasteners
M - NiCrFe AlloyP - StudAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Fracture
Micrographic detail of a longitudinal section of the stud, at the fracture surface, in the thread. It is possible to see primary precipitates (yellow) already cracked and intergranular propagation.
37
VIEW
ML00075 / Jun.2018
Hydrogen Cracking of IN 718 Subsea Fasteners
M - NiCrFe AlloyP - StudAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Intergranular Cracking
Micrography of a longitudinal section of the stud, at the fracture surface in the center of the thickness, showing a long secondary cracking (vertical in the left).
35
VIEW
ML00075 / Jun.2018
Hydrogen Cracking of IN 718 Subsea Fasteners
M - NiCrFe AlloyP - StudAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Secondary Cracks
Micrographic detail of the longitudinal section of the stud, at the secondary cracking.
26
VIEW
ML00075 / Jun.2018
Hydrogen Cracking of IN 718 Subsea Fasteners
M - NiCrFe AlloyP - StudAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Brittle Cracks