Damage

123 cases · 2129 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Damage — sub-branches

Brittle Behavior 12Corrosion 39Ductile Behavior 5Fabrication Defect 20Fatigue 12High Temperature 9Hydrogen 17Lack of Sealing 1Repair Defect 1Shooting Effect 4Wear 3

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Optical micrography of a longitudinal section of the fractured bolt, at the thread. The material is austenitic, free from carbides, and the threads were almost removed by the stress corrosion cracks.
756
VIEW
ML00157 / Feb.2020
Bolts Under Chloride SCC Conditions
M - Austenitic Stainless SteelP - BoltAp - Oil and GasCd - Stress Corrosion
Cm - Oxalic Acid Electrolytic EtchDf - Stress Corrosion Cracks
Concrete steel strand general view, presenting fracture of several wires and a corroded aspect. The full part is composed by 19 strands, each strand using 7 wires, and each wire about 5 mm diameter.
834
VIEW
ML00155 / Jan.2020
Failure of a Prestressed Concrete Steel Strand
M - High Carbon SteelP - Wire RopeAp - StructureCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - General View
Polished cross-section showing rounded graphite nodules within a ferritic matrix, bordered by an irregular oxidized region at the surface edge.
910
VIEW
ML00001 / Dec.2017
Thermal Fatigue of Cast Iron
M - Nodular Cast IronP - CastAp - SiderurgyCd - Thermal Fatigue
Cm - Nital Etched Micrography by OMDf - Oxide Layer
Vertical piping in a corrosive oil producing system of a FPSO. The line is a nominal diameter 14" sch 10S (pipe thickness about 5 mm) and the flanged branch line is a 2" nominal diameter welded to the main pipe using a weldolet (forged fitting). The fatigue induced cracking occurred longitudinal to the main pipe, originated at the margem of the weld interface with the pipe.
1480
VIEW
ML00150 / Dec.2018
Vibration Induced Fatigue in a SS Oil Piping
M - Duplex Stainless SteelP - PipingAp - FPSOCd - Vibration Induced Fatigue
Cm - Aspect Before AnalysisDf - General View
Gas piping. Aspect of a branching line 2" ND, lateral to a horizontal main pipe ND 8", welded using a weldolet. The cracking started at the margin of the weld in the upper part of the pipe, where the weld crossed the longitudinal direction of the pipe, perpendicular to the branch.
932
VIEW
ML00149 / Dec.2018
Vibration Induced Fatigue in a Gas Piping
M - Low Carbon SteelP - Piping spoolAp - FPSOCd - Vibration Induced Fatigue
Cm - Aspect Before AnalysisDf - Cracking
Aspect of the barrel nut that is broken in a brittle way (without plastic deformation). The Nut diameter is 1", the nut length is 2" and the bolt thread is 1/2" (nominal diameter).
753
VIEW
ML00148 / Sep.2018
Brittle Fracture of a 420 SS Barrel Nut
M - Martensitic Stainless SteelP - Barrel NutAp - LiftingCd - Heat Treatment Defect
Cm - Aspect Before AnalysisDf - General View
Red painted device where the 50 mm x 50 mm 6061 T6 aluminum alloy plate was positioned (in the circle). The image presents the target, positioned 100 meters far from the gun, after the shot and the projectile perforated the plate.
478
VIEW
ML00145 / Sep.2018
Impact of a .380 Winchester on 6061 T6 Plate
M - Aluminum Magnesium SiliconP - Rolled PlateAp - StructureCd - Pierced
Cm - Aspect Before AnalysisDf - General View
Macroscopic aspect of the outer diameter of the flanged sleeve presenting adhered products at the surface. The flanged sleeve was manufactured by centrifugal casting in a lean duplex stainless steel and it was externally coated by thermal spray (TS) in a position of sealing. After 5 years in service the system suffered leakage.
569
VIEW
ML00147 / Aug.2018
WC Layer Detached from a Cast Lean Duplex
M - Lean Duplex Stainless SteelP - Centrifugal CastingAp - ShipCd - Lack of Sealing
Cm - Aspect Before AnalysisDf - External Surface

More from these cases

ML00157 — Bolts Under Chloride SCC ConditionsM - Austenitic Stainless SteelP - BoltAp - Oil and GasCd - Stress Corrosion
Aspect of a 5/16" bolt manufactured in an AISI 316 austenitic stainless steel, that was also operating inside the pressure vessel, but was not yet damaged. It is a hexagonal head bolt, 1 1/2" long, fastened with a hexagonal nut and a lock washer.
118
VIEW
ML00157 / Feb.2020
Bolts Under Chloride SCC Conditions
M - Austenitic Stainless SteelP - BoltAp - Oil and GasCd - Stress Corrosion
Cm - Aspect Before AnalysisDf - General View
Low magnification micrography, by optical microscope, of the longitudinal section of a damaged bolt, in the center of the thickness. The microstructure is austenitic, free from carbides.
100
VIEW
ML00157 / Feb.2020
Bolts Under Chloride SCC Conditions
M - Austenitic Stainless SteelP - BoltAp - Oil and GasCd - Stress Corrosion
Cm - Oxalic Acid Electrolytic EtchDf - Austenite
Micrography, by optical microscope, of the longitudinal section of a damaged bolt, in the center of the thickness. The microstructure is austenitic, free from carbides, strain hardened. The hardness values of the material are from 200HV1 to 300HV1, that meets the class 2 of strenght (ASTM A193 B8M class 2).
79
VIEW
ML00157 / Feb.2020
Bolts Under Chloride SCC Conditions
M - Austenitic Stainless SteelP - BoltAp - Oil and GasCd - Stress Corrosion
Cm - Nital Etched Micrography by OMDf - Strain Hardened
Detail of the strain hardened austenitic microstructure. Micrography by optical microscope, of the longitudinal section of a bolt, in the center of the thickness.
76
VIEW
ML00157 / Feb.2020
Bolts Under Chloride SCC Conditions
M - Austenitic Stainless SteelP - BoltAp - Oil and GasCd - Stress Corrosion
Cm - Oxalic Acid Electrolytic EtchDf - Strain Hardened
Aspect of a broken 5/16" bolt that was operating inside the pressure vessel in a condition that exceeds the limits of use of the AISI 316 steel. The fracture is located close to the position where there was the bolt head and the threads were "removed" close to the fracture surface.
75
VIEW
ML00157 / Feb.2020
Bolts Under Chloride SCC Conditions
M - Austenitic Stainless SteelP - BoltAp - Oil and GasCd - Stress Corrosion
Cm - Aspect Before AnalysisDf - Fracture

+8 more from this case →

ML00155 — Failure of a Prestressed Concrete Steel StrandM - High Carbon SteelP - Wire RopeAp - StructureCd - Corrosion Fatigue
General aspect of the degradated wires of the strand, most part presenting rust and rupture.
107
VIEW
ML00155 / Jan.2020
Failure of a Prestressed Concrete Steel Strand
M - High Carbon SteelP - Wire RopeAp - StructureCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - General View
General aspect of the degradated wires of the strand, most part presenting rust and rupture. There are two mais aspects of the degradation: wire thickness reduction by corrosion and cracks creating a longitudinal fracture of several wires.
96
VIEW
ML00155 / Jan.2020
Failure of a Prestressed Concrete Steel Strand
M - High Carbon SteelP - Wire RopeAp - StructureCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - Fracture
Micrography of a wire in a longitudinal section, presenting a predominantly oearlitic structure, highly strained. The wires did not present any coating.
104
VIEW
ML00155 / Jan.2020
Failure of a Prestressed Concrete Steel Strand
M - High Carbon SteelP - Wire RopeAp - StructureCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Longitudinal Section
Higher magnification detail of the predominantly pearlitic microstructure of the wire.
88
VIEW
ML00155 / Jan.2020
Failure of a Prestressed Concrete Steel Strand
M - High Carbon SteelP - Wire RopeAp - StructureCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Predominantly Pearlitic
Macrography of a typical corroded wire in a longitudinal section, showing loss of thickness by corrosion.
75
VIEW
ML00155 / Jan.2020
Failure of a Prestressed Concrete Steel Strand
M - High Carbon SteelP - Wire RopeAp - StructureCd - Corrosion Fatigue
Cm - NItal Etched MacroDf - Corrosion

+36 more from this case →

ML00001 — Thermal Fatigue of Cast IronM - Nodular Cast IronP - CastAp - SiderurgyCd - Thermal Fatigue
Flat casting product presenting several thermal fatigue cracks all thorugh the surfaces. 1" thicknes.
171
VIEW
ML00001 / Dec.2017
Thermal Fatigue of Cast Iron
M - Nodular Cast IronP - CastAp - SiderurgyCd - Thermal Fatigue
Cm - Transverse Section AspectDf - Cracks Transverse to the Surface
Detail of figure 2, showing multiple fatigue cracks due to thermal cycles.
136
VIEW
ML00001 / Dec.2017
Thermal Fatigue of Cast Iron
M - Nodular Cast IronP - CastAp - SiderurgyCd - Thermal Fatigue
Cm - NItal Etched MacroDf - Cracks Transverse to the Surface
The 1" flat casting product presents a ferritic perlitic matrix and graphite nodules.
112
VIEW
ML00001 / Dec.2017
Thermal Fatigue of Cast Iron
M - Nodular Cast IronP - CastAp - SiderurgyCd - Thermal Fatigue
Cm - Nital Etched Micrography by OMDf - Graphite in Nodules
Center of the flat casting product, presenting nodular graphite and ferritic perlitic matrix.
113
VIEW
ML00001 / Dec.2017
Thermal Fatigue of Cast Iron
M - Nodular Cast IronP - CastAp - SiderurgyCd - Thermal Fatigue
Cm - Nital Etched Micrography by OMDf - Predominantly Ferritic Matrix
Nodular cast iron presenting a ferritic perlitic matrix.
109
VIEW
ML00001 / Dec.2017
Thermal Fatigue of Cast Iron
M - Nodular Cast IronP - CastAp - SiderurgyCd - Thermal Fatigue
Cm - Nital Etched Micrography by OMDf - Matrix of ferrite and pearlite

+4 more from this case →

ML00150 — Vibration Induced Fatigue in a SS Oil PipingM - Duplex Stainless SteelP - PipingAp - FPSOCd - Vibration Induced Fatigue
Macrography of the section transverse to the ND 14" main pipe (that is only 5mm thick) and to the ND 2" branch that is a weldolet fitting welded to the main pipe and flange. This image is interesting because it shows clearly how thin is the pipe compared with the fitting thickness and the large amount of welding required to assure a full penetration weld in the weldolet.
220
VIEW
ML00150 / Dec.2018
Vibration Induced Fatigue in a SS Oil Piping
M - Duplex Stainless SteelP - PipingAp - FPSOCd - Vibration Induced Fatigue
Cm - NaOH Electrolytic Etched MacroDf - Transverse Section
Transverse section of the 14" pipe in the center of the 2" branch using a weldolet fitting welded to the main pipe. The internal side of the pipe is to the top of the figure and the through wall fatigue cracking is located at the margem of the weld. It is possible to see that it is a full penetration weld and the fitting thickness is several times larger than the pipe thickness.
174
VIEW
ML00150 / Dec.2018
Vibration Induced Fatigue in a SS Oil Piping
M - Duplex Stainless SteelP - PipingAp - FPSOCd - Vibration Induced Fatigue
Cm - Electrolytically Etched MacroDf - Crack
Detail of the fatigue cracking, staring from the margin of the weld. The crack propagated though wall of the pipe (5 mm). The larger thickness of the weldolet requires a large amount of deposited weld metal, about 20 mm that is 4 times the pipe thickness. It is an interesting aspect to be considered by designers.
176
VIEW
ML00150 / Dec.2018
Vibration Induced Fatigue in a SS Oil Piping
M - Duplex Stainless SteelP - PipingAp - FPSOCd - Vibration Induced Fatigue
Cm - Electrolytically Etched MacroDf - Fatigue Crack
After cutting the pipe and opening the crack, the fracture appearance shows a clean fracture, flat, starting from the margem of the weld of the pipe (right side of the figure), and propagating through wall into the pipe (aproximately 5 mm thickness). The external side of the pipe is to the right side of the figure (presenting the weld finishing) and the internal side of the pipe is to the left side of the figure.
176
VIEW
ML00150 / Dec.2018
Vibration Induced Fatigue in a SS Oil Piping
M - Duplex Stainless SteelP - PipingAp - FPSOCd - Vibration Induced Fatigue
Cm - Fracture Surface AspectDf - Fracture
The same fracture appearance of the previous figure, looking at a higher magnification by scanning electron microscopy. The fracture is clean, flat, starting in the right side of the figure, at the margem of the weld and propagating into the pipe thickness. The external side of the pipe is to the right side of the figure and the internal side of the pipe is to the left side of the figure.
154
VIEW
ML00150 / Dec.2018
Vibration Induced Fatigue in a SS Oil Piping
M - Duplex Stainless SteelP - PipingAp - FPSOCd - Vibration Induced Fatigue
Cm - Fractography by SEMDf - Fracture

+29 more from this case →

ML00149 — Vibration Induced Fatigue in a Gas PipingM - Low Carbon SteelP - Piping spoolAp - FPSOCd - Vibration Induced Fatigue
Gas piping. Aspect of a branching line 2" ND with a flange, lateral to a main pipe ND 8", welded using a weldolet. The cracking is at the margin of the weld.
115
VIEW
ML00149 / Dec.2018
Vibration Induced Fatigue in a Gas Piping
M - Low Carbon SteelP - Piping spoolAp - FPSOCd - Vibration Induced Fatigue
Cm - Aspect Before AnalysisDf - General View
Micrography of a transverse section of the seamless pipe, presenting a ferritic-pearlitic structure.
84
VIEW
ML00149 / Dec.2018
Vibration Induced Fatigue in a Gas Piping
M - Low Carbon SteelP - Piping spoolAp - FPSOCd - Vibration Induced Fatigue
Cm - Nital Etched Micrography by OMDf - Ferrite and Pearlite
Micrography of a transverse section of the seamless pipe, presenting a ferritic-pearlitic structure.
70
VIEW
ML00149 / Dec.2018
Vibration Induced Fatigue in a Gas Piping
M - Low Carbon SteelP - Piping spoolAp - FPSOCd - Vibration Induced Fatigue
Cm - Nital Etched Micrography by OMDf - Ferrite and Pearlite
Gas piping. Aspect of a branching line 2" ND, lateral to a horizontal main pipe ND 8", welded using a weldolet. In the lower part of the branch there are no cracks.
61
VIEW
ML00149 / Dec.2018
Vibration Induced Fatigue in a Gas Piping
M - Low Carbon SteelP - Piping spoolAp - FPSOCd - Vibration Induced Fatigue
Cm - Aspect Before AnalysisDf - Welded Joint
Aspect of the brach line viewed from the internal side of the main pipe, after cuting. It is possible to see that the pipe was perforated by a thermal cutting (looking the finishing aspect of the edge of the hole). The weldolet was welded only from the external side of the pipe.
62
VIEW
ML00149 / Dec.2018
Vibration Induced Fatigue in a Gas Piping
M - Low Carbon SteelP - Piping spoolAp - FPSOCd - Vibration Induced Fatigue
Cm - Aspect Before AnalysisDf - Internal Surface

+13 more from this case →

ML00148 — Brittle Fracture of a 420 SS Barrel NutM - Martensitic Stainless SteelP - Barrel NutAp - LiftingCd - Heat Treatment Defect
Visual aspect of both sides of the fractures. They present a macroscopically brittle aspect, with chevron marks indicating the starting point at the thinner edge of the thread.
81
VIEW
ML00148 / Sep.2018
Brittle Fracture of a 420 SS Barrel Nut
M - Martensitic Stainless SteelP - Barrel NutAp - LiftingCd - Heat Treatment Defect
Cm - Aspect Before AnalysisDf - Fracture
The fracture is flat, in the region of the lower resistant section, presenting no macroscopic evidences of plastic deformation. The starting point of the fracture is indicated by the chevron marks.
62
VIEW
ML00148 / Sep.2018
Brittle Fracture of a 420 SS Barrel Nut
M - Martensitic Stainless SteelP - Barrel NutAp - LiftingCd - Heat Treatment Defect
Cm - Fracture Surface AspectDf - Chevron Marks
Low magnification micrography of the nut in the longitudinal section, presenting the machined internal thread and a banded microstructure.
55
VIEW
ML00148 / Sep.2018
Brittle Fracture of a 420 SS Barrel Nut
M - Martensitic Stainless SteelP - Barrel NutAp - LiftingCd - Heat Treatment Defect
Cm - Kalling Etched Micrography by OMDf - Banded Structure
Microstructural aspect of a longitudinal section of the nut, in the middle of the thickness. Martensitic structure, banded.
46
VIEW
ML00148 / Sep.2018
Brittle Fracture of a 420 SS Barrel Nut
M - Martensitic Stainless SteelP - Barrel NutAp - LiftingCd - Heat Treatment Defect
Cm - Kalling Etched Micrography by OMDf - Banded Structure
Microstructural detail of the banded structure. The rough aspect of the band is created by the carbides (better seen in the higher magnification image) in the segregation band.
38
VIEW
ML00148 / Sep.2018
Brittle Fracture of a 420 SS Barrel Nut
M - Martensitic Stainless SteelP - Barrel NutAp - LiftingCd - Heat Treatment Defect
Cm - Kalling Etched Micrography by OMDf - Banded Structure

+15 more from this case →

ML00145 — Impact of a .380 Winchester on 6061 T6 PlateM - Aluminum Magnesium SiliconP - Rolled PlateAp - StructureCd - Pierced
Aspect of a typical .308 Winchester projectile, similar to the one adopted to shot the plate, cut in a longitudinal section. It is a Cu alloy case filled with Pb-Sb.
61
VIEW
ML00145 / Sep.2018
Impact of a .380 Winchester on 6061 T6 Plate
M - Aluminum Magnesium SiliconP - Rolled PlateAp - StructureCd - Pierced
Cm - Longitudinal Section AspectDf - Longitudinal Section
Aspect of the 3/8" thickness plate, 50 mm x 50 mm, of the aluminum alloy plate, in the face of impact with the projectile. The plate was perforated by the bullet.
52
VIEW
ML00145 / Sep.2018
Impact of a .380 Winchester on 6061 T6 Plate
M - Aluminum Magnesium SiliconP - Rolled PlateAp - StructureCd - Pierced
Cm - Aspect Before AnalysisDf - General View
Micrography of the plate in a section, in the middle of the thickness. The aligned pitting is associated to the chemical etch of inclusions and second phases. The structure is granular but the grain boundaries do not appear at that magnification, originally 50x.
50
VIEW
ML00145 / Sep.2018
Impact of a .380 Winchester on 6061 T6 Plate
M - Aluminum Magnesium SiliconP - Rolled PlateAp - StructureCd - Pierced
Cm - Keller Etched Micrography by OMDf - Aligned particles
Micrography of the plate in a section, in the middle of the thickness, in a position where the plate was not affected by the shot. The microstructure is granular although the grain boundaries are not resolvable at this magnification. The black spots are localized corrosion in aligned particles.
49
VIEW
ML00145 / Sep.2018
Impact of a .380 Winchester on 6061 T6 Plate
M - Aluminum Magnesium SiliconP - Rolled PlateAp - StructureCd - Pierced
Cm - Keller Etched Micrography by OMDf - Aligned particles
Micrographic detail of the plate in the middle of the thickness. At this magnification it is possible to see the grain boundaries and the black spots are localized etching in aligned particles.
43
VIEW
ML00145 / Sep.2018
Impact of a .380 Winchester on 6061 T6 Plate
M - Aluminum Magnesium SiliconP - Rolled PlateAp - StructureCd - Pierced
Cm - Keller Etched Micrography by OMDf - Granular structure

+45 more from this case →

ML00147 — WC Layer Detached from a Cast Lean DuplexM - Lean Duplex Stainless SteelP - Centrifugal CastingAp - ShipCd - Lack of Sealing
Detail of the external surface of the sleeve where the surface coating was detached, creating a lack of sealing condition.
67
VIEW
ML00147 / Aug.2018
WC Layer Detached from a Cast Lean Duplex
M - Lean Duplex Stainless SteelP - Centrifugal CastingAp - ShipCd - Lack of Sealing
Cm - Surface AspectDf - External Surface
General view of the 10" diameter flanged sleeve, 1/2" wall thickness, manufactured by centrifugal casting of lean duplex stainless steel (DSS), Alloy 2304 (without Mo), with an external coating applied by thermal spray (TS). The sleeve is assembled in a shaft. The internal environment is oil and a seal box is assembled in the external side that is wet with seawater.
56
VIEW
ML00147 / Aug.2018
WC Layer Detached from a Cast Lean Duplex
M - Lean Duplex Stainless SteelP - Centrifugal CastingAp - ShipCd - Lack of Sealing
Cm - Aspect Before AnalysisDf - General View
Longitudinal slice of the flanged sleeve, 180 mm long, in a macrography presenting the 1/2" tubular wall thickness where the sealing was applied. The external surface of the sleeve (seawater wet) is in the left side of the figure and the internal surface (oiled) is in the right side. The flange is to the top of the figure.
52
VIEW
ML00147 / Aug.2018
WC Layer Detached from a Cast Lean Duplex
M - Lean Duplex Stainless SteelP - Centrifugal CastingAp - ShipCd - Lack of Sealing
Cm - Longitudinal Section AspectDf - General View
Macrographic aspect of the sleeve longitudinal section where the coating was applied in the external side (top of the figure). It is possible to see that the sleeve was manufactured by centrifugal casting, with elongated grains from the external side, and equiaxial grains close to the internal side (bottom of the figure). There is a weaved interface between the sleeve and the first layer of thermal spray coating, 1 mm thick; and a second layer of thermal spray coating, 0.2mm thick (almost imperceptible at this low magnification).
49
VIEW
ML00147 / Aug.2018
WC Layer Detached from a Cast Lean Duplex
M - Lean Duplex Stainless SteelP - Centrifugal CastingAp - ShipCd - Lack of Sealing
Cm - NaOH Electrolytic Etched MacroDf - Coating Layer
Micrography of a longitudinal section of the sleeve, at the external surface where there are two layers of coating. The electrolytic etch evidenced the duplex stainless steel substrate (bottom of the figure) and the weave interface of the substrate and the first thermal spray layer, about 1 mm thick, in a stainless steel. The surface layer, of tugnsten carbide, about 0.2 mm thick, is black and not clearly visible in this figure.
50
VIEW
ML00147 / Aug.2018
WC Layer Detached from a Cast Lean Duplex
M - Lean Duplex Stainless SteelP - Centrifugal CastingAp - ShipCd - Lack of Sealing
Cm - NaOH Electrolytic Etched MicroDf - External Surface

+24 more from this case →