Longitudinal Section

39 cases · 68 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Capture method: Optical Microscope clear all

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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
Micrography of the longitudinal section of the bolt, at the bottom of the thread fillet, showing that the fracture is intergranular in this position.
71
VIEW
ML00074 / Jun.2018
Hydrogen Cracking of a 17-4 PH Subsea Bolt
M - Precipitation Hardened Stainless SteelP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Longitudinal Section
Micrography of a longitudinal section of the 1" plate, in the center of the thickness, presenting a refined ferritic perlitic microstructure. Banded.
10
VIEW
ML00063 / Apr.2017
EH36 1" Plate for Structure
M - CMn SteelP - Rolled PlateAp - ShipCd - Typical manufacturing
Cm - Nital Etched Micrography by OMDf - Longitudinal Section
Detail of the longitudinal section of the ring, showing a fully ferritic structure.
619
VIEW
ML00057 / Apr.2017
Low Carbon Steel of Segment Ring
M - Low Carbon SteelP - Machined PartAp - AutomotiveCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Longitudinal Section
Micrography of a longitudinal section of the pipe showing that the carbon steel pipe is slightly banded and there is a decarburized layer at the solid solution welded interface. The stainless steel structure (in the right side of the figure) is not revealed using the Nital etch.
124
VIEW
ML00056 / May.2018
Seamless Tube Externally Cladded with SS
M - Carbon Steel / Stainless SteelP - CladdingAp - Pulp and PaperCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Longitudinal Section
The micrography of the tube shows a granular structure and light deformation lines. No evidences of corrosion from the external surface (upper side of the figure) or internal surface (lower side of the figure).
440
VIEW
ML00043 / Apr.2017
CuNi Condenser Tube
M - CupronickelP - Seamless tubeAp - Heat ExchangerCd - Removed From Service
Cm - FeCl3+HCl+H2O Etched MicroDf - Longitudinal Section
13Cr SS longitudinal section micrography, at the collapsed region, showing a ferritic matrix structure (overtempered) with the previous austenite grain boundaries decorated by phases (carbides and probably martensite islands), indicating that the material was exposed to a high tempering temperature that created a partial austenitizing condition. It explains the material low toughness and lower strenght (than required).
436
VIEW
ML00039 / Apr.2017
Collapse in Tubular 13Cr
M - Martensitic Stainless SteelP - Seamless PipeAp - Oil and GasCd - Heat Treatment Defect
Cm - Kalling Etched Micrography by OMDf - Longitudinal Section
The micrography in the longitudinal section in the middle of the thickness shows a light banding. Quenched and tempered structure.
346
VIEW
ML00037 / Jun.2017
LAS Forging for Pump Body
M - Low Alloy Medium Carbon QTP - Heat Treated PartAp - O&G Well DrillingCd - Typical manufacturing
Cm - Nital Etched Micrography by OMDf - Longitudinal Section

More from these cases

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
ML00057 — Low Carbon Steel of Segment RingM - Low Carbon SteelP - Machined PartAp - AutomotiveCd - Removed From Service
Longitudinal section of the ring, showing a fully ferritic structure.
128
VIEW
ML00057 / Apr.2017
Low Carbon Steel of Segment Ring
M - Low Carbon SteelP - Machined PartAp - AutomotiveCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Longitudinal Section
The longitudinal section of the ring reveals a very fine ferritic structure.
115
VIEW
ML00057 / Apr.2017
Low Carbon Steel of Segment Ring
M - Low Carbon SteelP - Machined PartAp - AutomotiveCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Longitudinal Section
ML00056 — Seamless Tube Externally Cladded with SSM - Carbon Steel / Stainless SteelP - CladdingAp - Pulp and PaperCd - Removed From Service
Micrographic detail of the interface in the longitudinal section of the pipe showing the Vickers (300g) microhardness values, close to the interface in the carbon steel side and in the stainless steel side. Although the Nital etch does not allow to reveal the structure in the stainless steel side, the high hardness values show that the structure is different.
113
VIEW
ML00056 / May.2018
Seamless Tube Externally Cladded with SS
M - Carbon Steel / Stainless SteelP - CladdingAp - Pulp and PaperCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Longitudinal Section
Micrography of the interface between the carbon steel that is strongly etched by the electrolytic oxalic acid (in the left side of the figure) and the stainless steel, in the longitudinal section of the pipe. There is a strain hardened layer very close to the interface, at the stainless steel side.
79
VIEW
ML00056 / May.2018
Seamless Tube Externally Cladded with SS
M - Carbon Steel / Stainless SteelP - CladdingAp - Pulp and PaperCd - Removed From Service
Cm - Micrography by OM using A262 Method ADf - Longitudinal Section
ML00039 — Collapse in Tubular 13CrM - Martensitic Stainless SteelP - Seamless PipeAp - Oil and GasCd - Heat Treatment Defect
13Cr SS in the longitudinal section, at the collapsed region. Non uniform structure (ferritic matrix and decorated prior austenite grain boundaries) that evidences an usuitable heat treatment during fabrication, and explains the material low strenght.
53
VIEW
ML00039 / Apr.2017
Collapse in Tubular 13Cr
M - Martensitic Stainless SteelP - Seamless PipeAp - Oil and GasCd - Heat Treatment Defect
Cm - Kalling Etched Micrography by OMDf - Longitudinal Section