Raw Material

8 cases · 137 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Microstructure: Bainite clear all

Raw Material — sub-branches

Carburized 1Chromium Plated 1Forging 1Pipe 3Rod 1Rolled Bar 1Rolled Plate 1Tube 3Welded Part 1

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Aspect of the waterwall during removal of the leaking tube. The leakage was detected, by visual inspection, from the outside of the boiler.
1675
VIEW
ML00163 / Jun.2020
Corrosion Fatigue of a Boiler Waterwall Tube
M - Low Carbon SteelP - Seamless tubeAp - BoilerCd - Corrosion Fatigue
Cm - Field photoDf - General View
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
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
Micrographic detail of the longitudinal section of the tube, close to the external surface. The carburizing layer consists of a bainitic structure, with intergranular and intragranular carbide precipitation.
1185
VIEW
ML00107 / Dec.2017
Carburized 9Cr1MoV Superheater Tube
M - Heat Resistant SteelP - Seamless tubeAp - BoilerCd - Carburization
Cm - Nital Etched Micrography by OMDf - Carburized Layer
Scanning electron fractography of a chromium plated pin, close to the pin surface where the fatigue cracking started, showing intergranular morphology typical of a hydrogen embrittlement effect. It occurred because the low alloy pin was carburized, quenched and tempered, with a too high hardness structure, before the electrolytic plating.
837
VIEW
ML00081 / Aug.2017
Hydrogen Cracking of a Chromium Plated Carburized Pin
M - Low Alloy for Thermochemical TreatmentP - Chromium PlatedAp - AutomotiveCd - Hydrogen Embrittlement
Cm - Fractography by SEMDf - Brittle Fracture
The macrography of a longitudinal section of the pipe and connector, at the welded joint, shows that the welding was conducted from both side of the groove, starting from the ID and finishing from the OD, ID later machined flush. The cracking was detected by ultrasonic test and the macro shows that it is at the fusion line, growthing into the weld metal. See the schematic drawing in the next figure
535
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 MacroDf - Longitudinal Section
Macrography showing the different regions of a pipe-to-plate fillet weld. See the schematic drawing in the next image
954
VIEW
ML00052 / Apr.2017
Cold Cracks in API 5CT L80 Tube Welded to a Structural Part
M - Low Alloy SteelP - Seamless tubeAp - OffshoreCd - Welding Defect
Cm - NItal Etched MacroDf - Fracture
Mooring chain aspect, after several years of operation. Transverse cracking, revealed by dye check, close to the flash butt weld.
441
VIEW
ML00013 / Apr.2017
Welding Cracks in Mooring Chain
M - Low Alloy Low Carbon QTP - Welded PartAp - OffshoreCd - Welding Defect
Cm - Aspect by NDTDf - Crack

More from these cases

ML00163 — Corrosion Fatigue of a Boiler Waterwall TubeM - Low Carbon SteelP - Seamless tubeAp - BoilerCd - Corrosion Fatigue
Aspect of the sample removed from the waterwall, where the tube has leaked, presenting the crack in the membrane.
361
VIEW
ML00163 / Jun.2020
Corrosion Fatigue of a Boiler Waterwall Tube
M - Low Carbon SteelP - Seamless tubeAp - BoilerCd - Corrosion Fatigue
Cm - Field photoDf - Through Wall Cracking
Aspect of the tube internal surface after removal from the boiler, presenting multiple longitudinal cracks.
295
VIEW
ML00163 / Jun.2020
Corrosion Fatigue of a Boiler Waterwall Tube
M - Low Carbon SteelP - Seamless tubeAp - BoilerCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - Internal Surface
Aspect of the external surface of the leaking tube, after removal of the membrane.
262
VIEW
ML00163 / Jun.2020
Corrosion Fatigue of a Boiler Waterwall Tube
M - Low Carbon SteelP - Seamless tubeAp - BoilerCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - External Surface
Throught wall cracking of the waterwall tube at the leakage position, thick edged, The external surface of the tube was grounded to remove the membrane and the cracking is associated to the tube attachement.
242
VIEW
ML00163 / Jun.2020
Corrosion Fatigue of a Boiler Waterwall Tube
M - Low Carbon SteelP - Seamless tubeAp - BoilerCd - Corrosion Fatigue
Cm - Transverse Section AspectDf - Thick-edged rupture
Macrography of the transverse section of the tube, in a position where the cracking was not yet through wall. The internal tube surface shows multiple corrosion fatigue cracks, parallel, under the weld of the membrane, probably related to the cold side of the tube (the cracks opened to the boiler outside). The external side of the tube presenting a small crack at the margem of the weld, suggesting also the action of thermal stresses.
214
VIEW
ML00163 / Jun.2020
Corrosion Fatigue of a Boiler Waterwall Tube
M - Low Carbon SteelP - Seamless tubeAp - BoilerCd - Corrosion Fatigue
Cm - NItal Etched MacroDf - Multiple cracks

+18 more from this case →

ML00133 — Seam Welded Pipe Cladded with Alloy 625M - LAS / Ni AlloyP - Longitudinal Seam Welded PipeAp - Oil and GasCd - Welding
The 6 1/2" nominal diameter longitudinal seam welded pipe is internally cladded with Alloy 625. The pipe was manufactured by forming a cladded plate (probably welded by rolling) and welding it longitudinally. The pipe was heat treated (quenched and tempered) after the seam weld.
97
VIEW
ML00133 / May.2018
Seam Welded Pipe Cladded with Alloy 625
M - LAS / Ni AlloyP - Longitudinal Seam Welded PipeAp - Oil and GasCd - Welding
Cm - Aspect Before AnalysisDf - Welded Joint
The macrography of a longitudinal section shows the low alloy (C-Mn) steel pipe, internally cladded with Ni alloy clad plate.
72
VIEW
ML00133 / May.2018
Seam Welded Pipe Cladded with Alloy 625
M - LAS / Ni AlloyP - Longitudinal Seam Welded PipeAp - Oil and GasCd - Welding
Cm - Electrolytically Etched MacroDf - Longitudinal Section
Micrography of a longitudinal section of the pipe substrate, in low magnification, showing a uniform microstructure,
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 - Base Metal
Micrography of a longitudinal section of the pipe substrate showing a uniform bainitic microstructure obtained by the pipe quenching and tempering,
48
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 - Longitudinal Section
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

+12 more from this case →

ML00132 — Seamless Pipe Overlaid with Alloy 625M - LAS / Ni AlloyP - Seamless PipeAp - Oil and GasCd - Welding
The 4 1/2" nominal diameter seamless pipe internally overlaid with Alloy 625. This pipe corresponds to a 90° curve. The overlaid pipe was heat treated before and after bending. The final quenching and tempering heat treatment was conducted to meet API 5L X70 properties.
113
VIEW
ML00132 / May.2018
Seamless Pipe Overlaid with Alloy 625
M - LAS / Ni AlloyP - Seamless PipeAp - Oil and GasCd - Welding
Cm - Aspect Before AnalysisDf - Welded Joint
The macrography of a longitudinal section shows the low alloy (C-Mn) steel pipe, internally cladded by overlay in two layers.
88
VIEW
ML00132 / May.2018
Seamless Pipe Overlaid with Alloy 625
M - LAS / Ni AlloyP - Seamless PipeAp - Oil and GasCd - Welding
Cm - Electrolytically Etched MacroDf - Longitudinal Section
Micrography of a longitudinal section of the pipe substrate, in low magnification, showing a uniform microstructure,
79
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 - Base Metal
Micrography of a longitudinal section of the pipe substrate showing a uniform bainitic microstructure obtained by the pipe quenching and tempering,
72
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 - Longitudinal Section
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

+12 more from this case →

ML00107 — Carburized 9Cr1MoV Superheater TubeM - Heat Resistant SteelP - Seamless tubeAp - BoilerCd - Carburization
Micrography of the longitudinal section of the tube, close to the internal surface. A thick scale is evident, but no microstructural changes compared to the center of the tube.
183
VIEW
ML00107 / Dec.2017
Carburized 9Cr1MoV Superheater Tube
M - Heat Resistant SteelP - Seamless tubeAp - BoilerCd - Carburization
Cm - Nital Etched Micrography by OMDf - Bainite
Aspect of the superheater ND 1" tube that was in operation for about 35,000 hours and presented a thick deposit at the external surface.
211
VIEW
ML00107 / Dec.2017
Carburized 9Cr1MoV Superheater Tube
M - Heat Resistant SteelP - Seamless tubeAp - BoilerCd - Carburization
Cm - Aspect Before AnalysisDf - General View
Micrography of a longitudinal section of the tube in the center of the thickness, showing a ferritic-bainitic structure of this CrMoV steel.
156
VIEW
ML00107 / Dec.2017
Carburized 9Cr1MoV Superheater Tube
M - Heat Resistant SteelP - Seamless tubeAp - BoilerCd - Carburization
Cm - Nital Etched Micrography by OMDf - Bainite
Micrography of a longitudinal section of the tube in the center of the thickness, showing a ferritic-bainitic structure of this CrMoV steel.
137
VIEW
ML00107 / Dec.2017
Carburized 9Cr1MoV Superheater Tube
M - Heat Resistant SteelP - Seamless tubeAp - BoilerCd - Carburization
Cm - Nital Etched Micrography by OMDf - Bainite
Micrography of a longitudinal section of the tube in the center of the thickness, showing a ferritic-bainitic structure of this CrMoV steel.
142
VIEW
ML00107 / Dec.2017
Carburized 9Cr1MoV Superheater Tube
M - Heat Resistant SteelP - Seamless tubeAp - BoilerCd - Carburization
Cm - Nital Etched Micrography by OMDf - Bainite

+9 more from this case →

ML00081 — Hydrogen Cracking of a Chromium Plated Carburized PinM - Low Alloy for Thermochemical TreatmentP - Chromium PlatedAp - AutomotiveCd - Hydrogen Embrittlement
Aspect of three pins that were operating in a hydraulic system. Adjacent to the fracture of the broken pin (the one that is in the right side of the figure) it is possible to see multiple surface craks and detachment of the surface chromium layer.
88
VIEW
ML00081 / Aug.2017
Hydrogen Cracking of a Chromium Plated Carburized Pin
M - Low Alloy for Thermochemical TreatmentP - Chromium PlatedAp - AutomotiveCd - Hydrogen Embrittlement
Cm - Aspect Before AnalysisDf - General View
The aspect of the pin fracture surface shows that a fatigue crack propagated from the pin surface at the edge of a lubrication hole in the chromium plated pin.
83
VIEW
ML00081 / Aug.2017
Hydrogen Cracking of a Chromium Plated Carburized Pin
M - Low Alloy for Thermochemical TreatmentP - Chromium PlatedAp - AutomotiveCd - Hydrogen Embrittlement
Cm - Aspect Before AnalysisDf - Fatigue Fracture
Micrography of a longitudinal section of the pin, in the center. The low carbon content of the steel in the center of the pin makes the structure bainitic even though it was quenched and tempered after carburizing.
80
VIEW
ML00081 / Aug.2017
Hydrogen Cracking of a Chromium Plated Carburized Pin
M - Low Alloy for Thermochemical TreatmentP - Chromium PlatedAp - AutomotiveCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - In the Center of the Thickness
Micrographic detail of the bainitic structure in the center of the pin, that was quenched and tempered after carburizing.
75
VIEW
ML00081 / Aug.2017
Hydrogen Cracking of a Chromium Plated Carburized Pin
M - Low Alloy for Thermochemical TreatmentP - Chromium PlatedAp - AutomotiveCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Bainite
Micrography of a longitudinal section of the pin, at the surface. The pin was carburized, quenched and tempered (yellow diffuse layer at the surface, 0.5 mm of extension) and a white layer of hard chromium plating is evident.
108
VIEW
ML00081 / Aug.2017
Hydrogen Cracking of a Chromium Plated Carburized Pin
M - Low Alloy for Thermochemical TreatmentP - Chromium PlatedAp - AutomotiveCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Carburized Layer

+11 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
Schematic drawing presenting the longitudinal section of the pipe and connector at the welded joint
105
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 - Identification drawingDf - Longitudinal Section
Hot cracking at the fusion line of the connector side, in a welded joint between a forging and a pipe, in a macrographic sample. The region of the heat affected zone of the connector presents a dendritic aspect suggesting that the forging reduction rate of the connector was not too high and did not broke the cast structure.
110
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 MacroDf - Welded Joint
The connector was welded to the pipe from both (internal and external) sides, a PWHT was applied and the part was machined. The UT indication was detected during final inspection.
78
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 - Aspect Before AnalysisDf - General View
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 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

+11 more from this case →

ML00052 — Cold Cracks in API 5CT L80 Tube Welded to a Structural PartM - Low Alloy SteelP - Seamless tubeAp - OffshoreCd - Welding Defect
Schematic drawing presenting the different regions of a pipe-to-plate fillet weld.
71
VIEW
ML00052 / Apr.2017
Cold Cracks in API 5CT L80 Tube Welded to a Structural Part
M - Low Alloy SteelP - Seamless tubeAp - OffshoreCd - Welding Defect
Cm - Identification drawingDf - Fracture
Macrography of the fillet welded joint between the 3" ND tube and the 3/4" thick plate. See the schematic drawing in the next figure
56
VIEW
ML00052 / Apr.2017
Cold Cracks in API 5CT L80 Tube Welded to a Structural Part
M - Low Alloy SteelP - Seamless tubeAp - OffshoreCd - Welding Defect
Cm - NItal Etched MacroDf - Welded Joint
Schematic drawing presenting the position of the cracking, at the margin of the weld in the tube and underbead.
47
VIEW
ML00052 / Apr.2017
Cold Cracks in API 5CT L80 Tube Welded to a Structural Part
M - Low Alloy SteelP - Seamless tubeAp - OffshoreCd - Welding Defect
Cm - Identification drawingDf - Welded Joint
The micrography shows the region underbead, of the tube HAZ, responsible for the hydrogen cracking (fracture in the right side of the photo - black). The hardness of the HAZ is about 600 HV.
55
VIEW
ML00052 / Apr.2017
Cold Cracks in API 5CT L80 Tube Welded to a Structural Part
M - Low Alloy SteelP - Seamless tubeAp - OffshoreCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Cracking
Low carbon plate base metal presenting the ferritic perlitic structure.
55
VIEW
ML00052 / Apr.2017
Cold Cracks in API 5CT L80 Tube Welded to a Structural Part
M - Low Alloy SteelP - Seamless tubeAp - OffshoreCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Base Metal

+13 more from this case →

ML00013 — Welding Cracks in Mooring ChainM - Low Alloy Low Carbon QTP - Welded PartAp - OffshoreCd - Welding Defect
Micrography of a longitudinal section of the mooring chain in the base metal. The low magnification reveals the banded structure of the rolled bar. The base metal microstructure is bainitic..
79
VIEW
ML00013 / Apr.2017
Welding Cracks in Mooring Chain
M - Low Alloy Low Carbon QTP - Welded PartAp - OffshoreCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Banded Structure
Micrographic detail of the bainitic microstructure of the base metal in the longitudinal section.
72
VIEW
ML00013 / Apr.2017
Welding Cracks in Mooring Chain
M - Low Alloy Low Carbon QTP - Welded PartAp - OffshoreCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Bainite
Micrography of a longitudinal section of the mooring chain at the flash welded region. The banded structure is deformed by the upset, close to the weld metal that is ferritic-bainitic.
61
VIEW
ML00013 / Apr.2017
Welding Cracks in Mooring Chain
M - Low Alloy Low Carbon QTP - Welded PartAp - OffshoreCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Bainitic Ferrite
Micrographic detail of the ferritic-bainitic weld metal, autogenous flash butt weld.
56
VIEW
ML00013 / Apr.2017
Welding Cracks in Mooring Chain
M - Low Alloy Low Carbon QTP - Welded PartAp - OffshoreCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Bainitic Ferrite
Welded region etched to reveal impurities. The banded structure creates a continuous network parallel to the weld metal.
50
VIEW
ML00013 / Apr.2017
Welding Cracks in Mooring Chain
M - Low Alloy Low Carbon QTP - Welded PartAp - OffshoreCd - Welding Defect
Cm - Micro by OM, picric acid+FeCl3+H2O etchDf - Segregated Regions

+3 more from this case →