Atlas

13 cases · 34 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Standard: ASTM Capture method: Optical Microscope Detail focus: Martensite clear all

Results

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Grain coarsened martensitic heat affected zone. The hardness values about 270HV10 indicates that the joint was post welding heat treated (PWHT).
97
VIEW
ML00178 / Jan.2022
Cold cracks in Cr-Mo Welded Forging
M - CrMo SteelP - ForgingAp - O&G Well DrillingCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Martensite
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
Micrography of the shaft very close to the surface, in a heat treated position. Graphite in nodules. Dark blue martensitic microstructure around the nodules, brown yellow martensite and white islands of martensitic with retained austenite microstructure.
65
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by OMDf - Martensite
Micrographic detail of the nut longitudinal section presenting the large carbides (white islands) in the segregation band, and small precipitates all through the martensite matrix, indicating that this high carbon steel was tempered in a high temperature. The 36HRc hardness also confirms this high tempering temperature.
39
VIEW
ML00148 / Sep.2018
Brittle Fracture of a 420 SS Barrel Nut
M - Martensitic Stainless SteelP - Barrel NutAp - LiftingCd - Heat Treatment Defect
Cm - Kalling Etched Micrography by OMDf - Martensite
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
Microstructure of the stud in the longitudinal section, out of a region of segregation, where the tempered martensitic microstructure appears more uniform.
72
VIEW
ML00136 / Jun.2018
Hydrogen Cracks of Subsea Studs
M - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Martensite
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.
111
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
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

More from these cases

ML00154 — High Strength Cast Iron CrankshaftM - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Micrographic detail of the graphite in nodules, dark blue martensitic microstructure around the nodules, brown yellow martensite and white yellow islands of martensitic with retained austenite microstructure.
61
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by OMDf - Martensite
Micrography of the shaft below the heat treated surface. At this position, in the middle of the hardened layer , it is possible to see also white regions of ferrite, very close to the graphite nodules.
47
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by OMDf - Martensite
Micrographic detail of the hardened layer, presenting the graphite nodules, brown and yellow martensite regions and white areas of ferrite, close to the nodules.
47
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by OMDf - Martensite
Micrography of the shaft below the heat treated surface. At this position, close to the limit of the hardened layer , it is possible to see the brown yellow martensite and ferrite around the graphite nodules.
39
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by OMDf - Martensite
Micrographic detail of the brown yellow martensite and ferrite around the graphite nodules.
39
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by OMDf - Martensite
ML00139 — Hydrogen Fracture of a 17-4 PH Allen BoltM - Precipitation Hardened Stainless SteelP - Allen BoltAp - SubseaCd - Hydrogen Embrittlement
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. 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
Micrography of a longitudinal section of the bolt, at the fracture (top of the figure), in the middle of the thickness. The fracture is macroscopically flat and there are some regions that present a transgranular morphology of the fracture.
45
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, in the center of a non-broken bolt that operated in the same assembling, presenting an aged martensitic structure, similar to the broken bolt.
38
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

+1 more from this case →

ML00136 — Hydrogen Cracks of Subsea StudsM - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Micrographic detail of the martensitic structure of the stud in the longitudinal section, out of a region of segregation, where the microstructure appears more uniform and the microhardness is about 370HV (50g).
62
VIEW
ML00136 / Jun.2018
Hydrogen Cracks of Subsea Studs
M - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Martensite
ML00130 — Fatigue Fracture of Overloaded BoltsM - Low Alloy Medium Carbon QTP - FastenerAp - O&G Well DrillingCd - Mechanical Fatigue
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
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