Microstructure

8 cases · 39 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Product: Pipe Standard: API Capture method: Optical Microscope clear all

Microstructure — sub-branches

Austenite 2Bainite 2Bainitic HAZ 1Banded Structure 1Clad Interface 17Columnar Grains 1Equiaxial Grains 1Ferrite and Pearlite 2Fusion Line 5Grain refined structure 2Martensite 3Overtempered Structure 1Prior Austenite Boundaries Decorated 1

Results

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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
Micrography of the pipe transverse section presenting a predominatly ferritic-perlitic microstructure.
132
VIEW
ML00140 / May.2019
Preferential Corrosion of Pipe Seam Weld
M - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Cm - Nital Etched Micrography by OMDf - Ferrite and Pearlite
Image by scanning electron microscopy of the metallurgically bonded interface of the internally cladded pipe. It is a longitudinal seam welded pipe, with substrate in low alloy steel X65 and clad plate in Alloy 625 (welded by a solid state process). The region is a detail in the side of the Ni alloy clad plate where a grain refinement has occurred probably due to recrystallization of a strain hardened region during later heat treatment. The microhardness of this region is a lot higher than the value obtained out of this region, in the clad plate.
904
VIEW
ML00133 / May.2018
Seam Welded Pipe Cladded with Alloy 625
M - LAS / Ni AlloyP - Longitudinal Seam Welded PipeAp - Oil and GasCd - Welding
Cm - Oxalic Acid Electrolytic EtchDf - Clad Interface
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
Micrographic detail of the AISI 4130 forging, 5/8" thickness, close to the welded region, in the longitudinal section. Bainitic and tempered martensitic structure.
47
VIEW
ML00072 / Jan.2018
Liquation Cracks in a High Strength Joint
M - Low Alloy Medium Carbon QTP - Longitudinal Seam Welded PipeAp - O&G Well DrillingCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Martensite
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
Micrographic detail of the fusion line of the second pass (not reheated). The HAZ is bainitic and the weld metal microstructure is predominantly formed by acicular ferrite.
51
VIEW
ML00053 / Mar.2017
SAW Longitudinal Seam of X70 Pipe
M - Microalloyed SteelP - Longitudinal Seam Welded PipeAp - SubseaCd - Welding
Cm - Nital Etched Micrography by OMDf - Fusion Line
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

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
ML00140 — Preferential Corrosion of Pipe Seam WeldM - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Micrographic detail of the predominatly ferritic-perlitic microstructure. Pipe transverse section.
95
VIEW
ML00140 / May.2019
Preferential Corrosion of Pipe Seam Weld
M - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Cm - Nital Etched Micrography by OMDf - Ferrite and Pearlite
ML00133 — Seam Welded Pipe Cladded with Alloy 625M - LAS / Ni AlloyP - Longitudinal Seam Welded PipeAp - Oil and GasCd - Welding
Micrographic detail of a longitudinal section of the pipe substrate showing a uniform bainitic microstructure,
50
VIEW
ML00133 / May.2018
Seam Welded Pipe Cladded with Alloy 625
M - LAS / Ni AlloyP - Longitudinal Seam Welded PipeAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Bainite
Micrography 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.
55
VIEW
ML00133 / May.2018
Seam Welded Pipe Cladded with Alloy 625
M - LAS / Ni AlloyP - Longitudinal Seam Welded PipeAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Clad Interface
Micrography 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.
51
VIEW
ML00133 / May.2018
Seam Welded Pipe Cladded with Alloy 625
M - LAS / Ni AlloyP - Longitudinal Seam Welded 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. The metallurgical bonding of the claded plate to the substrate is evident since there are no voids or defects.
47
VIEW
ML00133 / May.2018
Seam Welded Pipe Cladded with Alloy 625
M - LAS / Ni AlloyP - Longitudinal Seam Welded 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 - 266 HV100g), very close to the interface inside the clad plate (dot 2 - 429 HV100g) and a little far from the interface inside the Ni clad plate (dot 3 - 358 HV100g).
51
VIEW
ML00133 / May.2018
Seam Welded Pipe Cladded with Alloy 625
M - LAS / Ni AlloyP - Longitudinal Seam Welded PipeAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Clad Interface

+8 more from this case →

ML00132 — Seamless Pipe Overlaid with Alloy 625M - LAS / Ni AlloyP - Seamless PipeAp - Oil and GasCd - Welding
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
Low magnification micrography of a longitudinal section of the pipe at the interface,with oxalic acid electrolytic method that overetchs the low alloy steel structure (to the left side of the image), and reveals the structure of the clad interface.
49
VIEW
ML00132 / May.2018
Seamless Pipe Overlaid with Alloy 625
M - LAS / Ni AlloyP - Seamless PipeAp - Oil and GasCd - Welding
Cm - Oxalic Acid Electrolytic EtchDf - Clad Interface

+2 more from this case →

ML00072 — Liquation Cracks in a High Strength JointM - Low Alloy Medium Carbon QTP - Longitudinal Seam Welded PipeAp - O&G Well DrillingCd - Welding Defect
Micrographic detail of the X65 pipe, 5/8" thickness, in the longitudinal section. The refined ferritic structure with bainitic bands is responsible for obtaining the 65 Ksi YS for a low carbon manganese ferritic structure.
48
VIEW
ML00072 / Jan.2018
Liquation Cracks in a High Strength Joint
M - Low Alloy Medium Carbon QTP - Longitudinal Seam Welded PipeAp - O&G Well DrillingCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Banded Structure
ML00053 — SAW Longitudinal Seam of X70 PipeM - Microalloyed SteelP - Longitudinal Seam Welded PipeAp - SubseaCd - Welding
Fusion line of the first pass (reheated in high temperature). The HAZ is bainitic and the weld metal microstructure is predominantly formed by acicular ferrite.
43
VIEW
ML00053 / Mar.2017
SAW Longitudinal Seam of X70 Pipe
M - Microalloyed SteelP - Longitudinal Seam Welded PipeAp - SubseaCd - Welding
Cm - Nital Etched Micrography by OMDf - Fusion Line
Micrographic detail of the fusion line of the first pass (reheated in high temperature). The HAZ is bainitic and the weld metal microstructure is predominantly formed by acicular ferrite.
37
VIEW
ML00053 / Mar.2017
SAW Longitudinal Seam of X70 Pipe
M - Microalloyed SteelP - Longitudinal Seam Welded PipeAp - SubseaCd - Welding
Cm - Nital Etched Micrography by OMDf - Fusion Line
Micrographic detail of the fusion line of the first pass (reheated in high temperature). The HAZ is bainitic and the weld metal microstructure is predominantly formed by acicular ferrite.
38
VIEW
ML00053 / Mar.2017
SAW Longitudinal Seam of X70 Pipe
M - Microalloyed SteelP - Longitudinal Seam Welded PipeAp - SubseaCd - Welding
Cm - Nital Etched Micrography by OMDf - Fusion Line
Micrographic detail of the fusion line of the second pass (not reheated). Bainitic HAZ and acicular ferrite in the weld metal.
45
VIEW
ML00053 / Mar.2017
SAW Longitudinal Seam of X70 Pipe
M - Microalloyed SteelP - Longitudinal Seam Welded PipeAp - SubseaCd - Welding
Cm - Nital Etched Micrography by OMDf - Fusion Line
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.
31
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