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Crevice Corrosion in a Subsea System — Aspect Before Analysis

111 images

TryO&G Well DrillingML00171corrosionOil and GasML00118brittle fractureDamageductile behaviorCorrosionfatigueFinished ProducthydrogenRaw Materialfractureembrittlementstress corrosion
Microstructure: Tempered Martensite Standard: AISI Detail focus: Damage clear all
M

Material

79 classified

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P

Product

96 classified

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Ap

Application

37 classified

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C

Condition

84 classified

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Cm

Capture method

52 classified

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Df

Detail focus

208 classified

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The Materials
Image Database

111 images
Detail of the flat fracture from the notch at the bottom of the recess. No plastic deformation.
113
VIEW
ML00182 / Jul.2022
Brittle Fracture of a LAS Fixing Rod
M - Low Alloy Medium Carbon QTP - StemAp - Mechanical IndustryCd - Brittle Fracture
Cm - Aspect Before AnalysisDf - Brittle Fracture
General view of the cylindrical valve body, 6 5/8" nominal diameter, showing a transverse straight crack at the external surface.
406
VIEW
ML00162 / Apr.2020
Valve Body Crack Growth from Weld Defects
M - Low Alloy Medium Carbon QTP - Valve BodyAp - O&G Well DrillingCd - Fatigue Induced by a Defect
Cm - Aspect Before AnalysisDf - Crack
Macroscopic view of the fracture in the pipe body. In the bottom of the figure, the fracture of the pipe shows a thicker thickness, revealing that this is the pipe region that was first damaged by bending (buckling). In the top of the figure, the fracture shows a (ductile) shearing mechanism and the thickness is thinner, as will be better observed in the macrography.
39
VIEW
ML00159 / Mar.2020
Collapse of a Drill Pipe
M - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Ductile Behavior
Cm - Aspect Before AnalysisDf - Fracture
Macroscopic view of the fracture surface showing that there is a flat appearance of the fracture close to the bottom of the thread (upper side of the figure) and a flat, but rough appearance in the center of the stud. No evidences of corrosion in the thread fillets indicating that the stud was protected.
59
VIEW
ML00136 / Jun.2018
Hydrogen Cracks of Subsea Studs
M - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Aspect Before AnalysisDf - Brittle Fracture
Fractographic analysis by scanning electron microscopy of the stud fracture surface after opening the cracks. Brittle intergranular morphology with dimples and quasecleavage micromechanisms indicate that the internal cracks, intergranular, occurred by a hydrogen embrittlement effect during electroplating, and the ductile aspects are probably associated to overloading during torque.
517
VIEW
ML00127 / May.2018
Hydrogen Cracks of Cadmium Plated Studs
M - Low Alloy Medium Carbon QTP - Allen StudAp - Oil and GasCd - Hydrogen Embrittlement
Cm - Fractography by SEMDf - Fracture
Aspect of the fracture surface of the bolt, after cleaning with a plastic brush. Although there is a layer of oxides it is possible to see the intergranular morphology of the fracture, typical of a hydrogen embrittlement mechanism.
1154
VIEW
ML00126 / Mar.2018
Hydrogen Fracture of Subsea Allen Bolts
M - Low Alloy Medium Carbon QTP - Coated ProductAp - SubseaCd - Hydrogen Embrittlement
Cm - Fractography by SEMDf - Intergranular Fracture
Microscopic image by scanning electron microscope (SEM) of the ring surface that presented pites under fouling deposits.
522
VIEW
ML00124 / Feb.2018
MIC of a Martensitic Valve Ring
M - Martensitic Stainless SteelP - ForgingAp - EnergyCd - Brittle Behavior
Cm - Surface Aspect by SEMDf - Pitting
Micrography of the external surface of the tubular equipment, close to the fracture position (it is to the top of the figure), showing multiple cracks, typical of a corrosion fatigue mechanism.
861
VIEW
ML00082 / Dec.2017
Corrosion Fatigue of a Drilling Tool
M - Low Alloy Medium Carbon QTP - Tubular ForgingAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Multiple cracks

More from these cases

ML00182 — Brittle Fracture of a LAS Fixing RodM - Low Alloy Medium Carbon QTP - StemAp - Mechanical IndustryCd - Brittle Fracture
Micrography presenting segregation bands (less etched) in a tempered martensitic microstructure.
81
VIEW
ML00182 / Jul.2022
Brittle Fracture of a LAS Fixing Rod
M - Low Alloy Medium Carbon QTP - StemAp - Mechanical IndustryCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Segregated Regions
Micrographic detail of the segregated bands.
61
VIEW
ML00182 / Jul.2022
Brittle Fracture of a LAS Fixing Rod
M - Low Alloy Medium Carbon QTP - StemAp - Mechanical IndustryCd - Brittle Fracture
Cm - Micro by OM, picric acid+FeCl3+H2O etchDf - Segregated Regions
Micrographic etch for revealing previous austenite grain boundaries, that shows the impurities.
54
VIEW
ML00182 / Jul.2022
Brittle Fracture of a LAS Fixing Rod
M - Low Alloy Medium Carbon QTP - StemAp - Mechanical IndustryCd - Brittle Fracture
Cm - Micro by OM, picric acid+FeCl3+H2O etchDf - Segregated Regions
Flat fracture, no plastic deformation, at the notch in the recess.
63
VIEW
ML00182 / Jul.2022
Brittle Fracture of a LAS Fixing Rod
M - Low Alloy Medium Carbon QTP - StemAp - Mechanical IndustryCd - Brittle Fracture
Cm - Aspect Before AnalysisDf - Brittle Fracture
Fractographic image of the actual rod rupture, showing that the material fractured by an intergranular micromechanism, evidencing a tempered martensite embrittlement.
59
VIEW
ML00182 / Jul.2022
Brittle Fracture of a LAS Fixing Rod
M - Low Alloy Medium Carbon QTP - StemAp - Mechanical IndustryCd - Brittle Fracture
Cm - Fractography by SEMDf - Intergranular Fracture

+6 more from this case →

ML00162 — Valve Body Crack Growth from Weld DefectsM - Low Alloy Medium Carbon QTP - Valve BodyAp - O&G Well DrillingCd - Fatigue Induced by a Defect
Penetrant test (dye check) image of the cracks at the surface of the actuator hole, viewed from inside of the body after the longitudinal cut. The aspect of the cracks at the hole, close to the internal side of the valve, is not the same as the aspect of the cracks at the external side (a straigth line), suggesting that the original cracks had propagated by fatigue through wall. The penetrant did not stained too much at the cracked area, indicating that the cracks are not too deep in this position, or are not fully opened to the surface.
62
VIEW
ML00162 / Apr.2020
Valve Body Crack Growth from Weld Defects
M - Low Alloy Medium Carbon QTP - Valve BodyAp - O&G Well DrillingCd - Fatigue Induced by a Defect
Cm - Aspect by NDTDf - Crack
Magnetic particle test of the same cracks at the edge of the actuator hole, viewed from inside of the body. The cracks appeared more clearly with this test than with the penetrant test, suggesting that the cracks are not fully opened to the surface.
60
VIEW
ML00162 / Apr.2020
Valve Body Crack Growth from Weld Defects
M - Low Alloy Medium Carbon QTP - Valve BodyAp - O&G Well DrillingCd - Fatigue Induced by a Defect
Cm - Aspect by NDTDf - Crack
Longitudinal section of the cylindrical body showing two pieces with the cracks, close to the position of the actuator hole. The valve body thickness is 40 mm at the location where the cracks appeared.
53
VIEW
ML00162 / Apr.2020
Valve Body Crack Growth from Weld Defects
M - Low Alloy Medium Carbon QTP - Valve BodyAp - O&G Well DrillingCd - Fatigue Induced by a Defect
Cm - Longitudinal Section AspectDf - Crack
Macrography of the longitudinal section of the valve body, at the cracked position, a little far from the actuator hole. The valve body is 40 mm thick at this position and it is possible to see that at this position only one region is welded in repair, close to the outer surface (top), and there is a crack, transverse to the thickness, that is difficult to see with this magnification and that is clearly the propagation in fatigue.
47
VIEW
ML00162 / Apr.2020
Valve Body Crack Growth from Weld Defects
M - Low Alloy Medium Carbon QTP - Valve BodyAp - O&G Well DrillingCd - Fatigue Induced by a Defect
Cm - Nital Etched Micrography by OMDf - Fatigue Crack
Macrographic detail of the longitudinal section of the valve body, at the cracked position, a little far from the actuator hole. There is a straight crack, transverse to the thickness that clearly propagated by fatigue mechanism, from the region where the welding defects were created.
27
VIEW
ML00162 / Apr.2020
Valve Body Crack Growth from Weld Defects
M - Low Alloy Medium Carbon QTP - Valve BodyAp - O&G Well DrillingCd - Fatigue Induced by a Defect
Cm - NItal Etched MacroDf - Fatigue Crack

+10 more from this case →

ML00159 — Collapse of a Drill PipeM - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Ductile Behavior
Macrography of a longitudinal section of the pipe at the fracture position, as ground, showing in the rigth side the thicker thickness and several secondary cracks opened to the external side of the pipe (created during bending), and in the left side the shearing mechanism and the thinner thickness.
39
VIEW
ML00159 / Mar.2020
Collapse of a Drill Pipe
M - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Ductile Behavior
Cm - Longitudinal Section AspectDf - Plastic Deformation
Macrography of a longitudinal section of the pipe at the fracture position, in the thicker thickness. The external side of the pipe (OD) is to the rigth side of the figure, and the internal side of the pipe is to the left of the figure. There are several secondary cracks, opened to the OD, created during bending.
37
VIEW
ML00159 / Mar.2020
Collapse of a Drill Pipe
M - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Ductile Behavior
Cm - NItal Etched MacroDf - Plastic Deformation
Macrography of a longitudinal section of the pipe at the fracture position, in the thinner thickness. The external side of the pipe (OD) is to the left side of the figure, and the internal side of the pipe is to the rigth of the figure. The fracture occurred by shearing the pipe in a single event (probably due to tensile stresses during removal).
37
VIEW
ML00159 / Mar.2020
Collapse of a Drill Pipe
M - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Ductile Behavior
Cm - NItal Etched MacroDf - Ductile Fracture
Macrographic detail of the longitudinal section of the pipe at the fracture position, in the thicker thickness. The several secondary cracks, opened to the OD, were created during bending and shows evidences of compression, responsible for the increase in the pipe thickness.
33
VIEW
ML00159 / Mar.2020
Collapse of a Drill Pipe
M - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Ductile Behavior
Cm - NItal Etched MacroDf - Ductile Fracture
Micrography of the longitudinal section of the pipe, at the thicker part of the fracture, showing several secondary cracks opened to the external side of the pipe. There are no problems in the material structure and the cracks are associated to large plastic deformation.
36
VIEW
ML00159 / Mar.2020
Collapse of a Drill Pipe
M - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Ductile Behavior
Cm - Nital Etched Micrography by OMDf - Ductile Crack

+5 more from this case →

ML00136 — Hydrogen Cracks of Subsea StudsM - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Fractographic aspect of the stud fracture surface, by scanning electron microscopy, close to the bottom of the thread fillet. In the center of the image it is possible to see secondary cracks with intergranular morphology.
59
VIEW
ML00136 / Jun.2018
Hydrogen Cracks of Subsea Studs
M - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Fractography by SEMDf - Brittle Fracture
Fractographic detail by scanning electron microscopy of the secondary cracks with intergranular morphology.
47
VIEW
ML00136 / Jun.2018
Hydrogen Cracks of Subsea Studs
M - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Fractography by SEMDf - Secondary Cracks
Macroscopic detail of the stud, adjacent to the fracture, showing that there are several secondary cracks at the bottom of the thread fillets, without any deformation evidence. This reveals a brittle material behavior, although the hardness measured at the stud end revealed 33HRc, as should be expected by the material specification.
59
VIEW
ML00136 / Jun.2018
Hydrogen Cracks of Subsea Studs
M - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Aspect Before AnalysisDf - Secondary Cracks
Macrography of a stud longitudinal sectiion at the fracture position (top of the figure). It is possible to see a large secondary crack at the bottom of the thread fillet adjacent to the fracture surface, without any deformation evidence. This reveals a brittle material behavior, although the hardness measured at the stud end revealed 33HRc, as should be expected by the material specification.
56
VIEW
ML00136 / Jun.2018
Hydrogen Cracks of Subsea Studs
M - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - NItal Etched MacroDf - Secondary Cracks
Low magnification micrography of a stud longitudinal section in the first thread fillet adjacent to the fracture, presenting a large secondary crack without any deformation evidence. This reveals a brittle material behavior, although the hardness measured at the stud end revealed 33HRc, as should be expected by the material specification.
47
VIEW
ML00136 / Jun.2018
Hydrogen Cracks of Subsea Studs
M - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Secondary Cracks

+18 more from this case →

ML00127 — Hydrogen Cracks of Cadmium Plated StudsM - Low Alloy Medium Carbon QTP - Allen StudAp - Oil and GasCd - Hydrogen Embrittlement
Allen stud, 1/2" nominal diameter, cadmium plated and chromate treated, cracked during assembling external parts in a gate valve.
40
VIEW
ML00127 / May.2018
Hydrogen Cracks of Cadmium Plated Studs
M - Low Alloy Medium Carbon QTP - Allen StudAp - Oil and GasCd - Hydrogen Embrittlement
Cm - Aspect Before AnalysisDf - Fracture
Allen stud, cadmium plated and chromate treated. The fracture appearance is brittle.
38
VIEW
ML00127 / May.2018
Hydrogen Cracks of Cadmium Plated Studs
M - Low Alloy Medium Carbon QTP - Allen StudAp - Oil and GasCd - Hydrogen Embrittlement
Cm - Aspect Before AnalysisDf - Fracture
Fractographic analysis by scanning electron microscopy of the stud fracture surface after opening the cracks. Brittle intergranular morphology with dimples and quasecleavage micromechanisms indicate that the internal cracks, intergranuar, occurred by a hydrogen embrittlement effect during electroplating, and the ductile aspects are probably associated to overloading during torque.
37
VIEW
ML00127 / May.2018
Hydrogen Cracks of Cadmium Plated Studs
M - Low Alloy Medium Carbon QTP - Allen StudAp - Oil and GasCd - Hydrogen Embrittlement
Cm - Fractography by SEMDf - Intergranular Cracking
Micrography of the longitudinal section of the stud showing internal cracks, secondary (not the cracks that opened the fracture). It is evident that the cracking from the thread fillet, of a ductile aspect, presented a different aspect than the internal cracks, of a brittle aspect.
31
VIEW
ML00127 / May.2018
Hydrogen Cracks of Cadmium Plated Studs
M - Low Alloy Medium Carbon QTP - Allen StudAp - Oil and GasCd - Hydrogen Embrittlement
Cm - As polished micrographyDf - Cracks
Micrography of the longitudinal section of the stud showing a crack from the thread fillet, of a ductile aspect, opened during torque.
30
VIEW
ML00127 / May.2018
Hydrogen Cracks of Cadmium Plated Studs
M - Low Alloy Medium Carbon QTP - Allen StudAp - Oil and GasCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Fracture

+3 more from this case →

ML00126 — Hydrogen Fracture of Subsea Allen BoltsM - Low Alloy Medium Carbon QTP - Coated ProductAp - SubseaCd - Hydrogen Embrittlement
Detailed aspect of the fracture surface of the bolt, evidencing the intergranular morphology of the fracture (although with an oxide scale), typical of a hydrogen embrittlement mechanism.
114
VIEW
ML00126 / Mar.2018
Hydrogen Fracture of Subsea Allen Bolts
M - Low Alloy Medium Carbon QTP - Coated ProductAp - SubseaCd - Hydrogen Embrittlement
Cm - Fractography by SEMDf - Intergranular Fracture
Micrography of the longitudinal section of the bolt, at the fracture (top of the figure), starting from the bottom of the thread (to the left side of the figure). The presence of the coating at the bolt surface shows that the fracture occurred without corrosion. The rusted aspect of the fracture is associated to corrosion products after the rupture has occurred, also suggesting that the bolts were fractured and remained in service for some time after the failure occurred.
65
VIEW
ML00126 / Mar.2018
Hydrogen Fracture of Subsea Allen Bolts
M - Low Alloy Medium Carbon QTP - Coated ProductAp - SubseaCd - Hydrogen Embrittlement
Cm - As polished micrographyDf - Fracture
Micrography, after NItal etching, of the longitudinal section of the bolt, at the fracture (top of the figure), starting from the bottom of the thread (to the left side of the figure). The presence of the coating at the bolt surface shows that the fracture occurred without corrosion.
56
VIEW
ML00126 / Mar.2018
Hydrogen Fracture of Subsea Allen Bolts
M - Low Alloy Medium Carbon QTP - Coated ProductAp - SubseaCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Fracture
Micrography of the longitudinal section of the bolt, in the center of the thickness, showing at the fracture surface (top of the figure), secondary cracks that are perpendicular to the fracture, associated to segregation bands.
55
VIEW
ML00126 / Mar.2018
Hydrogen Fracture of Subsea Allen Bolts
M - Low Alloy Medium Carbon QTP - Coated ProductAp - SubseaCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Secondary Cracks
Micrographic detail of the longitudinal section of the bolt, in the center of the thickness, showing the secondary cracks associated to segregation bands.
63
VIEW
ML00126 / Mar.2018
Hydrogen Fracture of Subsea Allen Bolts
M - Low Alloy Medium Carbon QTP - Coated ProductAp - SubseaCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Secondary Cracks
ML00124 — MIC of a Martensitic Valve RingM - Martensitic Stainless SteelP - ForgingAp - EnergyCd - Brittle Behavior
Macroscopic aspect of the crack after cleaning the ring surface. Transverse cracks were identified associated to pitting corrosion.
44
VIEW
ML00124 / Feb.2018
MIC of a Martensitic Valve Ring
M - Martensitic Stainless SteelP - ForgingAp - EnergyCd - Brittle Behavior
Cm - Aspect Before AnalysisDf - Localized Corrosion
Microscopic details of the ring surface showing the fouling at the surface and localized corrosion under the deposits.
42
VIEW
ML00124 / Feb.2018
MIC of a Martensitic Valve Ring
M - Martensitic Stainless SteelP - ForgingAp - EnergyCd - Brittle Behavior
Cm - Surface Aspect by SEMDf - Pitting
Higher magnification of the localized corrosion, showing that there are cracks at the margin of the corroded region.
39
VIEW
ML00124 / Feb.2018
MIC of a Martensitic Valve Ring
M - Martensitic Stainless SteelP - ForgingAp - EnergyCd - Brittle Behavior
Cm - Surface Aspect by SEMDf - Pitting
SEM image showing a branching surface crack extending from a region of granular corrosion deposits into the polished substrate.
32
VIEW
ML00124 / Feb.2018
MIC of a Martensitic Valve Ring
M - Martensitic Stainless SteelP - ForgingAp - EnergyCd - Brittle Behavior
Cm - Surface Aspect by SEMDf - Pitting
Intergranular morphology inside the pitting and evidences of chemical attack (dissolution).
36
VIEW
ML00124 / Feb.2018
MIC of a Martensitic Valve Ring
M - Martensitic Stainless SteelP - ForgingAp - EnergyCd - Brittle Behavior
Cm - Surface Aspect by SEMDf - Pitting

+8 more from this case →

ML00082 — Corrosion Fatigue of a Drilling ToolM - Low Alloy Medium Carbon QTP - Tubular ForgingAp - O&G Well DrillingCd - Corrosion Fatigue
Drilling tool that broke close to the region of the male connector (pin end). The fracture is at the right side of the figure.
102
VIEW
ML00082 / Dec.2017
Corrosion Fatigue of a Drilling Tool
M - Low Alloy Medium Carbon QTP - Tubular ForgingAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - Fracture
The fracture was removed from the failed part and analyzed separately. The aspect of the fracture surface is presented. It is flat, with regions of fatigue propagation and with regions of erosion by washout (to the right side of the figure).
80
VIEW
ML00082 / Dec.2017
Corrosion Fatigue of a Drilling Tool
M - Low Alloy Medium Carbon QTP - Tubular ForgingAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - Fracture
Detail of the fracture surface presenting a fatigue propagation from the outside of the tool.
69
VIEW
ML00082 / Dec.2017
Corrosion Fatigue of a Drilling Tool
M - Low Alloy Medium Carbon QTP - Tubular ForgingAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - Fatigue Fracture
Detail of the fracture surface presenting erosion by a washout, because the equipment was pressurized when the cracking became through wall.
63
VIEW
ML00082 / Dec.2017
Corrosion Fatigue of a Drilling Tool
M - Low Alloy Medium Carbon QTP - Tubular ForgingAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - Washout
As polished micrography of the external surface of the tubular equipment, close to the fracture position (it is to the top of the figure), showing corrosion fatigue cracks. These are multiple cracks, paralel to the main fracture, slightly branched and fully filled with oxides.
51
VIEW
ML00082 / Dec.2017
Corrosion Fatigue of a Drilling Tool
M - Low Alloy Medium Carbon QTP - Tubular ForgingAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - As polished micrographyDf - Multiple cracks

+3 more from this case →

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The location of the threaded fitting started leaking after less than five years in service. Although the corrosion rate was not high, the localized material loss in the threaded surface of the carbon steel flange allowed the connection leakage.
770
VIEW
ML00184 / Apr.2023
Dissimilar Steels in a Threaded Connection
M - Low Carbon SteelP - ForgingAp - OffshoreCd - Localized Dissolution
Cm - Aspect Before AnalysisDf - General View
Front wheel 17 x 7J of a passenger vehicle (identified as WHEEL 1) that broke during a car accident on a road.
1645
VIEW
ML00183 / Dec.2022
Ductile Behavior of an Aluminum Wheel
M - Aluminum Silicon MagnesiumP - CastingAp - AutomotiveCd - Ductile Behavior
Cm - Aspect Before AnalysisDf - General View
Tool fixture 5" long, nominal diameter 2", presenting a recess 1/2" deep from two sides. The rupture occurred about 2" from the end of the rod. Scale in milimeters.
523
VIEW
ML00182 / Jul.2022
Brittle Fracture of a LAS Fixing Rod
M - Low Alloy Medium Carbon QTP - StemAp - Mechanical IndustryCd - Brittle Fracture
Cm - Aspect Before AnalysisDf - General View
Pinion of hypoid gearbox, assembled in a 1560-mm long shaft that operated during more than 60,000 hours, and removed from service due to unacceptable wear damage.
1028
VIEW
ML00181 / Apr.2022
Wear of a Carburized Hypoid Gear
M - Low Alloy for Thermochemical TreatmentP - Pinion-crown assemblyAp - ShipCd - Wear
Cm - Aspect Before AnalysisDf - General View
Aspect of the 3 1/2" diameter tube after the water leakage in high temperature.
963
VIEW
ML00180 / Mar.2022
Local Melting of Copper Cooling Tubes
M - Pure CopperP - Cooling TubeAp - SiderurgyCd - Overheating
Cm - Aspect Before AnalysisDf - General View
2" drain line from the main 10" line. The leakage occurred at the margin of the weld, a short time after the introduction of the reinforced ribs to reduce vibration.
642
VIEW
ML00179 / Feb.2022
Hydrides in Titanium Weld
M - Unalloyed TitaniumP - In Field WeldAp - Chemical IndustryCd - Hydride Formation
Cm - Field photoDf - General View
The drilling connector, 21" diameter, presented a crack at the margin of the weld in the forging side (left side of the weld in the figure).
748
VIEW
ML00178 / Jan.2022
Cold cracks in Cr-Mo Welded Forging
M - CrMo SteelP - ForgingAp - O&G Well DrillingCd - Welding Defect
Cm - Aspect Before AnalysisDf - General View
Macrography of the longitudinally seam weld of the 24" diameter tube, showing that it was welded from both sides and there is a segregation line in the center of the tube thickness.
737
VIEW
ML00177 / Dec.2021
Cr-Mo Seam Welded Tube
M - CrMo SteelP - Longitudinally Seam WeldedAp - Fired HeaterCd - Not according to spec
Cm - NItal Etched MacroDf - Seam
The titanium rotor blade of a flowmeter broke after two years in service in an acid environment, containing H2S.
340
VIEW
ML00176 / Nov.2021
Hydride Formation in a Titanium Blade
M - Unalloyed TitaniumP - BladeAp - Oil and GasCd - Hydride Formation
Cm - Aspect Before AnalysisDf - General View
Aspect of the wire rope, 1 1/2" diameter, presenting regions of flattened areas at the surface of the outer wires. It is a 6 x 19 Seale construction, right regular lay.
553
VIEW
ML00175 / Aug.2021
Localized External Wear of a Wire Rope
M - High Carbon SteelP - Wire RopeAp - Oil and GasCd - Wear
Cm - Aspect Before AnalysisDf - General View
The carcass was manufactured using niobium stabilized plates, grade AISI 347, with circumferential welds, where the through wall cracks were detected.
303
VIEW
ML00174 / Jul.2021
Carburization of a 347 SS Welded Joint
M - Austenitic Stainless SteelP - Fabrication WeldAp - EnergyCd - Carburization
Cm - Field photoDf - General View
Aged microstructure of the HP stainless steel, modified with 1%Nb, cast fitting, tubular, operating for 6 years in a furnace which design temperature is 1100°C. The material presented a network of primary carbides, white and grey, and an austenitic matrix with coalescing secondary precipitation. Some voids. The Vickers identation indicates a hardness value about 260HV 100g in the aged austenitic matrix.
493
VIEW
ML00173 / May.2021
Welding Cracks in an Aged HP Cast Fitting
M - Heat Resistant SteelP - Cast FtittingAp - PetrochemicalCd - Welding
Cm - Kalling Etched Micrography by OMDf - Microhardness identations

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