Ferritic pearlitic

7 cases · 14 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Capture method: Optical Microscope Detail focus: Close to the Internal Surface clear all

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Micrographic aspect, as polished, of the cast cylinder section at the fracture position (top of the figure), close to the internal surface (left side). It is possible to see large graphite flakes.
98
VIEW
ML00141 / Jul.2018
Brittle Fracture of a Corroded Gray Cast Iron
M - Gray Cast ironP - CastingAp - EngineCd - Brittle Fracture
Cm - As polished micrographyDf - Close to the Internal Surface
Micrographic detail of a transverse section of the tubing, close to the internal surface. Ferritic-pearlitic structure, refined.
20
VIEW
ML00116 / Jan.2018
CMn Steel Structural Tubing 6 mm thick
M - CMn SteelP - Seamless Round ShapeAp - StructureCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Close to the Internal Surface
Micrographic detail of a transverse section of the tubing, close to the internal surface. Ferritic-pearlitic structure. Very close to the surface the amount of ferrite is higher than in the center and the grain is coarser, due to a decarburization effect probably occurred when the surface was exposed to high temperature during manufacturing.
13
VIEW
ML00115 / Jan.2018
CMn Steel Structural Tubing 5 mm thick
M - CMn SteelP - Seamless Round ShapeAp - StructureCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Close to the Internal Surface
Micrography of a transverse section of the tubing, close to the internal surface. Ferritic-pearlitic structure, refined.
16
VIEW
ML00114 / Jan.2018
CMn Steel Structural Tubing 8 mm thick
M - CMn SteelP - Seamless Round ShapeAp - StructureCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Close to the Internal Surface
Micrography of a transverse section of the pipe, close to the internal surface (ID). The pipe presented a predominatly ferritic structure.
29
VIEW
ML00112 / Dec.2017
1" XXS Pipe Not Qualified For Low Temp
M - Low Carbon SteelP - Seamless PipeAp - RefineryCd - Not according to spec
Cm - Nital Etched Micrography by OMDf - Close to the Internal Surface
Micrography of a transverse section of the pipe, close to the internal surface (ID). Refined structure. Ferrite and pearlite.
64
VIEW
ML00111 / Dec.2017
3/4" XXS Pipe Not Qualified for Low Temp
M - Low Carbon SteelP - Seamless PipeAp - RefineryCd - Not according to spec
Cm - Nital Etched Micrography by OMDf - Close to the Internal Surface
The micrography of the longitudinal section of the tube, close to ID, shows the paralel cracks, filled with oxides, perpendicular to the surface.
229
VIEW
ML00104 / Dec.2017
Thermal Fatigue of a Boiler Tube
M - Low Carbon SteelP - Autogenously Welded TubeAp - BoilerCd - Thermal Fatigue
Cm - As polished micrographyDf - Close to the Internal Surface

More from these cases

ML00141 — Brittle Fracture of a Corroded Gray Cast IronM - Gray Cast ironP - CastingAp - EngineCd - Brittle Fracture
Micrography of the longitudinal section of the cylinder, at the internal diameter (left side of the figure), in contact with the treated cooling water, presenting large graphite flakes in a predominatly perlitic matrix.
50
VIEW
ML00141 / Jul.2018
Brittle Fracture of a Corroded Gray Cast Iron
M - Gray Cast ironP - CastingAp - EngineCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Close to the Internal Surface
Micrography of the corroded surface of the cast cylinder, with 0.5 mm penetrations, showing that the graphites are interconnected and create a notch morphology, critical for a material that presents 1% ductility.
31
VIEW
ML00141 / Jul.2018
Brittle Fracture of a Corroded Gray Cast Iron
M - Gray Cast ironP - CastingAp - EngineCd - Brittle Fracture
Cm - As polished micrographyDf - Close to the Internal Surface
Micrographic aspect of the cast cylinder section at the fracture position (top of the figure), close to the internal surface (left side). It is possible to see large graphite flakes.
23
VIEW
ML00141 / Jul.2018
Brittle Fracture of a Corroded Gray Cast Iron
M - Gray Cast ironP - CastingAp - EngineCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Close to the Internal Surface
Micrographic detail of the cast cylinder section at the fracture position (top of the figure), close to the internal surface (left side). It is possible to see a thick oxide layer at the internal surface, characteristic of 10 years operating with treated water, and the large graphite flakes interconnecting.
23
VIEW
ML00141 / Jul.2018
Brittle Fracture of a Corroded Gray Cast Iron
M - Gray Cast ironP - CastingAp - EngineCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Close to the Internal Surface
Micrographic detail of the cast cylinder section at the fracture position (top of the figure), close to the internal surface (left side), presenting the thick oxide layer at the internal surface and penetrating in the large graphite flakes, corroding the matrix and easily interconnecting the flakes with a localized effect as a notch.
24
VIEW
ML00141 / Jul.2018
Brittle Fracture of a Corroded Gray Cast Iron
M - Gray Cast ironP - CastingAp - EngineCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Close to the Internal Surface
ML00112 — 1" XXS Pipe Not Qualified For Low TempM - Low Carbon SteelP - Seamless PipeAp - RefineryCd - Not according to spec
Micrography of a transverse section of the pipe, close to the internal surface (ID). The pipe presented a predominatly ferritic structure.
22
VIEW
ML00112 / Dec.2017
1" XXS Pipe Not Qualified For Low Temp
M - Low Carbon SteelP - Seamless PipeAp - RefineryCd - Not according to spec
Cm - Nital Etched Micrography by OMDf - Close to the Internal Surface
ML00111 — 3/4" XXS Pipe Not Qualified for Low TempM - Low Carbon SteelP - Seamless PipeAp - RefineryCd - Not according to spec
Micrography of a transverse section of the pipe, close to the internal surface (ID). Refined structure, but not uniform. Ferrite and pearlite. The pearlite colonies appear in a network.
45
VIEW
ML00111 / Dec.2017
3/4" XXS Pipe Not Qualified for Low Temp
M - Low Carbon SteelP - Seamless PipeAp - RefineryCd - Not according to spec
Cm - Nital Etched Micrography by OMDf - Close to the Internal Surface