Microstructure

8 cases · 28 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Product: Seamless Pipe clear all

Microstructure — sub-branches

Austenite 3Bainite 1Bainitic HAZ 1Clad Interface 10Columnar Grains 1Equiaxial Grains 1Ferrite and Pearlite 3Grain refined structure 1Martensite 2Overtempered Structure 1Predominantly Ferritic 3Prior Austenite Boundaries Decorated 1

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Micrographic detail of the very refined ferritic structure of the base metal, in the longitudinal section, indicating that the material was heat treated, since no banding is not detectable at this magnification.
101
VIEW
ML00153 / Jan.2019
X52 in a Tubular Structure
M - CMn SteelP - Seamless PipeAp - StructureCd - Qualified
Cm - Nital Etched Micrography by OMDf - Grain refined structure
Image by scanning electron microscopy of the metallurgically bonded interface of the internally cladded pipe. It is a seamless pipe in a low alloy steel X70 cladded by welding overlay of Alloy 625 (by automatic GTAW process). The region is a detail of the interface inside the Ni alloy weld metal, presenting columnar grains and intragranular preciptation. The pipe was heat treated before bending (solution annealing) and after bending (quenching and tempering to meet X70 grade). The microhardness of this region is higher than the value obtained out of this region, in the overlay.
657
VIEW
ML00132 / May.2018
Seamless Pipe Overlaid with Alloy 625
M - LAS / Ni AlloyP - Seamless PipeAp - Oil and GasCd - Welding
Cm - Electrolytic Etch Micrography by SEMDf - Clad Interface
Micrography of a transverse section of the pipe, external diameter 33.4 mm schedule XXS, in the center of the 9.1 mm thickness. The structure is predominantly ferritic. Small amount of pearlite.
556
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 - Predominantly Ferritic
Micrography of a transverse section of the pipe, external diameter 26.7 mm, in the center of the 7.85mm thickness. Refined structure but not uniform. Ferrite and pearlite.
512
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 - Ferrite and Pearlite
Micrography of a longitudinal section of the pipe presenting a granular austenitic structure, typical of a solid solution annealing condition. No carbide precipitation.
62
VIEW
ML00012 / Aug.2017
Vibration Induced Fatigue in a 316/316L SS
M - Austenitic Stainless SteelP - Seamless PipeAp - OffshoreCd - Vibration Induced Fatigue
Cm - Micrography by OM using A262 Method ADf - Austenite
The microstructure of the pipe, presented in a longitudinal section, is an uniform tempered martensite.
105
VIEW
ML00068 / Sep.2020
Corrosion Fatigue of a 5" Drill Pipe
M - Low Alloy Medium Carbon QTP - Seamless PipeAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Martensite
13Cr SS in the longitudinal section, at the collapsed region. Detail of the 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.
48
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 - Prior Austenite Boundaries Decorated
Austenitic structure at the transverse section of the pipe, free from carbides.
277
VIEW
ML00014 / Apr.2017
Pitting Corrosion in 316SS Pipe
M - Austenitic Stainless SteelP - Seamless PipeAp - FPSOCd - Pitting Corrosion
Cm - Micrography by OM using A262 Method ADf - Austenite

More from these cases

ML00153 — X52 in a Tubular StructureM - CMn SteelP - Seamless PipeAp - StructureCd - Qualified
Micrographic detail of the bainitic structure of the coarse grain heat affected zone, close to the fusion line (to the top of the figure).
76
VIEW
ML00153 / Jan.2019
X52 in a Tubular Structure
M - CMn SteelP - Seamless PipeAp - StructureCd - Qualified
Cm - Nital Etched Micrography by OMDf - Bainitic HAZ
Micrographic detail of the weld metal in the last bead. The microstructure shows primary ferrite in the (previous austenite) grain boundaries, some regions of ferrite with aligned second phases and acicular ferrite in the center of the columnar grains.
51
VIEW
ML00153 / Jan.2019
X52 in a Tubular Structure
M - CMn SteelP - Seamless PipeAp - StructureCd - Qualified
Cm - Nital Etched Micrography by OMDf - Columnar Grains
Micrographic detail of the refined ferritic microstructure, with equiaxial grains, of the weld metal in the root, reheated by the fill pass. At this magnification it is possible to see that the agglomerated carbides ar located in ferritic grain boundaries.
67
VIEW
ML00153 / Jan.2019
X52 in a Tubular Structure
M - CMn SteelP - Seamless PipeAp - StructureCd - Qualified
Cm - Nital Etched Micrography by OMDf - Equiaxial Grains
ML00132 — Seamless Pipe Overlaid with Alloy 625M - LAS / Ni AlloyP - Seamless PipeAp - Oil and GasCd - Welding
Micrographic detail of a longitudinal section of the pipe substrate showing a uniform bainitic microstructure.
68
VIEW
ML00132 / May.2018
Seamless Pipe Overlaid with Alloy 625
M - LAS / Ni AlloyP - Seamless PipeAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Bainite
Micrography of a longitudinal section of the pipe at the overlay fusion line, with Nital etch that reveals only the low alloy steel structure, to the left side of the image.
67
VIEW
ML00132 / May.2018
Seamless Pipe Overlaid with Alloy 625
M - LAS / Ni AlloyP - Seamless PipeAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Clad Interface
Micrography of a longitudinal section of the pipe at the overlay fusion line, with Nital etch that reveals only the low alloy steel structure, to the left side of the image. Some decarburization of the low alloy steel substrate is evident since the microstructure is slightly different a little far from the interface.
66
VIEW
ML00132 / May.2018
Seamless Pipe Overlaid with Alloy 625
M - LAS / Ni AlloyP - Seamless PipeAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Clad Interface
Micrographic detail of a longitudinal section of the pipe at the interface with the clad plate, with Nital etch that reveals only the low alloy steel structure, to the left side of the image.
59
VIEW
ML00132 / May.2018
Seamless Pipe Overlaid with Alloy 625
M - LAS / Ni AlloyP - Seamless PipeAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Clad Interface
Micrography showing the positions of Vickers microhardness measurements in the longitudinal micrography, in the pipe steel substrate (dot 1 - 217 HV100g), very close to the interface inside the overlay (dot 2 - 370 HV100g) and a little far from the interface inside the Ni clad plate (dot 3 - 229 HV100g).
57
VIEW
ML00132 / May.2018
Seamless Pipe Overlaid with Alloy 625
M - LAS / Ni AlloyP - Seamless PipeAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Clad Interface

+5 more from this case →

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 external surface (OD). The pipe presented a predominatly ferritic structure.
31
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 - Predominantly Ferritic
Micrography of a transverse section of the pipe, close to the internal surface (ID). The pipe presented a predominatly ferritic structure.
21
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 - Predominantly Ferritic
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. Ferrite and pearlite. The structure is not uniform. There is a large variation in the ferritic grain size and the pearlite colonies appear forming a network.
39
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 - Ferrite and Pearlite
Micrography of a transverse section of the pipe, close to the external surface (OD). Refined structure. Ferrite and pearlite. The structure is not uniform. There is a large variation in the ferritic grain size.
28
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 - Ferrite and Pearlite
ML00039 — Collapse in Tubular 13CrM - Martensitic Stainless SteelP - Seamless PipeAp - Oil and GasCd - Heat Treatment Defect
The micrography of the 13Cr SS in the transverse section, at the collapsed region, shows 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).
32
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 - Overtempered Structure
The micrography of the 13Cr SS in the transverse section, far from the collapsed region, shows a uniform tempered martensitic structure.
32
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 - Martensite
ML00014 — Pitting Corrosion in 316SS PipeM - Austenitic Stainless SteelP - Seamless PipeAp - FPSOCd - Pitting Corrosion
Austenitic structure, free from carbides, exactly in the region of the pitting, indicating that the corrosion is not associated to the material microstructure.
261
VIEW
ML00014 / Apr.2017
Pitting Corrosion in 316SS Pipe
M - Austenitic Stainless SteelP - Seamless PipeAp - FPSOCd - Pitting Corrosion
Cm - Micrography by OM using A262 Method ADf - Austenite