Optical Microscope

4 cases · 41 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Product: Pipe Microstructure: Tempered Martensite clear all

Optical Microscope — sub-branches

Eletrolytically Etched Micrography by OM 6Kalling Etched Micrography by OM 9Micrography by OM 2Nital Etched Micrography by OM 24

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Micrography of the welded joint fusion line presenting the liquation cracking. The weld metal is in the right side (bottom) and the forged connector heat affected zone is in the left side (top).
83
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 - Cracking
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
Micrography of the base metal presenting a banded microstructure in the longitudinal section of the pipe.
51
VIEW
ML00066 / May.2017
GMAW Welded Joint in 9%Ni Alloy Steel
M - Nickel Alloy SteelP - Welded Testpiece for QualificationAp - PipelineCd - Welding
Cm - Nital Etched Micrography by OMDf - Base Metal
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).
437
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

More from these cases

ML00072 — Liquation Cracks in a High Strength JointM - Low Alloy Medium Carbon QTP - Longitudinal Seam Welded PipeAp - O&G Well DrillingCd - Welding Defect
The liquation crack is a hot crack in the base metal (at the HAZ) that induces a solidification crack in the weld metal.
66
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 - Weld Metal
Micrographic detail of the cracks at the fusion line of the welded joint, at the connector side. The cracking presents morphology of melting regions of impurities at grain boundaries of the large grains of the heat affected zone (HAZ).
57
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 - Fusion Line
The HAZ presents microcracks at previous austenite grain boundaries. These regions melted during welding and generated cracks associated to low melting temperature phases.
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 - Microcracks
The HAZ presents microcracks at previous austenite grain boundaries. These regions melted during welding and generated cracks associated to low melting temperature phases.
43
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 - Microcracks
Micrography of the AISI 4130 forging, 5/8" thickness, close to the welded region, in the longitudinal section.
42
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 - Base Metal Left Side

+7 more from this case →

ML00068 — Corrosion Fatigue of a 5" Drill PipeM - Low Alloy Medium Carbon QTP - Seamless PipeAp - O&G Well DrillingCd - Corrosion Fatigue
The micrography in the as polished condition of the longitudinal section of the pipe close to the washout, shows that at the tool mark tip (notch from the external surface) a fatigue crack already started from a corroded region (pitting).
187
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 - Micrography by OMDf - Pitting
Micrographic detail, in the as polished condition, of the corrosion fatigue crack.
90
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 - Micrography by OMDf - Fatigue Crack
The micrography of one of the (multiple) cracks shows the slightly irregular morphology of the cracking, typical of a corrosion-fatigue mechanism.
281
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 - Corrosion Cracking
Micrographic detail of the slightly irregular crack propagation, typical of a corrosion-fatigue mechanism.
76
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 - Corrosion Cracking
ML00066 — GMAW Welded Joint in 9%Ni Alloy SteelM - Nickel Alloy SteelP - Welded Testpiece for QualificationAp - PipelineCd - Welding
Micrographic detail of a longitudinal section of the base metal presenting a quenched and tempered microstructure.
49
VIEW
ML00066 / May.2017
GMAW Welded Joint in 9%Ni Alloy Steel
M - Nickel Alloy SteelP - Welded Testpiece for QualificationAp - PipelineCd - Welding
Cm - Nital Etched Micrography by OMDf - Base Metal
Micrographic detail of the low temperature heat affected zone of the pipe. The intercritical temperature (IC) is evident in the decorated grain boundaries of the previous austenite.
42
VIEW
ML00066 / May.2017
GMAW Welded Joint in 9%Ni Alloy Steel
M - Nickel Alloy SteelP - Welded Testpiece for QualificationAp - PipelineCd - Welding
Cm - Nital Etched Micrography by OMDf - Heat Affected Zone
Micrography of the fusion line close to the cap pass (CP). The weld metal (non etched) is in the left side.
43
VIEW
ML00066 / May.2017
GMAW Welded Joint in 9%Ni Alloy Steel
M - Nickel Alloy SteelP - Welded Testpiece for QualificationAp - PipelineCd - Welding
Cm - Nital Etched Micrography by OMDf - Fusion Line
Micrography of the heat affected zone, a little far from the fusion line, close to the base metal.
40
VIEW
ML00066 / May.2017
GMAW Welded Joint in 9%Ni Alloy Steel
M - Nickel Alloy SteelP - Welded Testpiece for QualificationAp - PipelineCd - Welding
Cm - Nital Etched Micrography by OMDf - Heat Affected Zone
Micrographic detail of the fusion line in the center of the thickness, where the heat affected zone was reheated by the subsequent passes.
34
VIEW
ML00066 / May.2017
GMAW Welded Joint in 9%Ni Alloy Steel
M - Nickel Alloy SteelP - Welded Testpiece for QualificationAp - PipelineCd - Welding
Cm - Nital Etched Micrography by OMDf - Fusion Line

+8 more from this case →

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.
54
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
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
13Cr SS in the transverse section, at the collapsed region, showing a non uniform structure that evidences an usuitable heat treatment during fabrication, and explains the material low strenght.
29
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 - Transverse Section
13Cr SS transverse 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).
29
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 - Transverse Section
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

+3 more from this case →