Damage

12 cases · 102 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Condition: Fatigue clear all

Damage — sub-branches

Crack 10Cracking 6Cracks 3Cracks Transverse to the Surface 4Ductile Fracture 2Fatigue Crack 19Fatigue Fracture 12Fatigue Striation 9Fracture 6Margin of the Weld Crack 3Multiple cracks 1Oxide Layer 2Pitting 5Plastic Deformation 3Pore 1Thermal Fatigue Cracks 7Through Wall Cracking 5Transgranular Cracking 3Transgranular Fracture 1

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Low magnification fractography by scanning electron microscopy, after a complete opening of the crack. At this magnification no micromechanism is evident.
51
VIEW
ML00167 / Aug.2020
Fatigue of a Flared Tubing Connection
M - Austenitic Stainless SteelP - TubingAp - EngineCd - Mechanical Fatigue
Cm - Fractography by SEMDf - 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
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
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 bolt fracture surface by scanning electron microscopy, (SEM) presenting striations that indicate a FATIGUE micromechanism. The bolt is of a medium strength (class 8.8) low alloy steel, medium carbon, quenched and tempered.
1123
VIEW
ML00130 / Jun.2018
Fatigue Fracture of Overloaded Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - O&G Well DrillingCd - Mechanical Fatigue
Cm - Fractography by SEMDf - Fatigue Fracture
Multiple thermal fatigue cracks at the welded joint between the smoke tube (vertical, internal diameter 248mm) and the tubesheet (horizontal, plate of 22 mm thickness). This is a view from the combustion chamber. The dye check tests revealed several parallel cracks.
1249
VIEW
ML00119 / Feb.2018
Thermal Fatigue of a Marine Boiler
M - Low Carbon SteelP - Fabrication WeldAp - ShipCd - Thermal Fatigue
Cm - Aspect by NDTDf - Thermal Fatigue Cracks
The macrography of a longitudinal section of the tube in the damaged area shows the circunferential cracks, from the internal and external sides of the tube. The outer diameter of the tube is in the top of the figure and the inner diameter is in the bottom of the figure. From the outside there are several paralel cracks, as well as from the inner side.
126
VIEW
ML00104 / Dec.2017
Thermal Fatigue of a Boiler Tube
M - Low Carbon SteelP - Autogenously Welded TubeAp - BoilerCd - Thermal Fatigue
Cm - NItal Etched MacroDf - Cracks
Micrographic detail of the fatigue cracking at the margin of the flange to shell fillet weld.
484
VIEW
ML00050 / Nov.2017
Fatigue Failure of a 316SS Pressure Stabilizer
M - Austenitic Stainless SteelP - Fabrication WeldAp - Chemical IndustryCd - Mechanical Fatigue
Cm - Micrography by OM using A262 Method ADf - Fatigue Crack

More from these cases

ML00167 — Fatigue of a Flared Tubing ConnectionM - Austenitic Stainless SteelP - TubingAp - EngineCd - Mechanical Fatigue
Flat aspect of the fracture. The striation micromechanism is revealed.
50
VIEW
ML00167 / Aug.2020
Fatigue of a Flared Tubing Connection
M - Austenitic Stainless SteelP - TubingAp - EngineCd - Mechanical Fatigue
Cm - Fractography by SEMDf - Fatigue Fracture
The thin striation is evident in the fracture surface, suggesting a high cycle fatigue, typically identified in vibration conditions.
45
VIEW
ML00167 / Aug.2020
Fatigue of a Flared Tubing Connection
M - Austenitic Stainless SteelP - TubingAp - EngineCd - Mechanical Fatigue
Cm - Fractography by SEMDf - Fatigue Striation
Detail of the striation micromechanism.
48
VIEW
ML00167 / Aug.2020
Fatigue of a Flared Tubing Connection
M - Austenitic Stainless SteelP - TubingAp - EngineCd - Mechanical Fatigue
Cm - Fractography by SEMDf - Fatigue Striation
When the fracture propagates, the striation becomes wider and with transgranular irregular steps.
47
VIEW
ML00167 / Aug.2020
Fatigue of a Flared Tubing Connection
M - Austenitic Stainless SteelP - TubingAp - EngineCd - Mechanical Fatigue
Cm - Fractography by SEMDf - Fatigue Fracture
Micrography of a longitudinal section of the flared tubing where the fracture occurred. The starting point of the fracture is associated to the external side of the tubing, where it was connected by a nut and there was a localized plastic deformation due to the fitting assembly.
33
VIEW
ML00167 / Aug.2020
Fatigue of a Flared Tubing Connection
M - Austenitic Stainless SteelP - TubingAp - EngineCd - Mechanical Fatigue
Cm - Oxalic Acid Electrolytic EtchDf - Transgranular Fracture

+1 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 →

ML00150 — Vibration Induced Fatigue in a SS Oil PipingM - Duplex Stainless SteelP - PipingAp - FPSOCd - Vibration Induced Fatigue
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
Fracture apperance by scanning electron microscopy of the region where the fatigue crack started, from the piping outside . The fracture is flat, presents some smashed regions close to the surface (to the right side) and there are some thin secondary cracks.
140
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 - Fatigue Fracture
Fracture detail by scanning electron microscopy of the region where the cracking started, from the piping outside . The fracture is flat and shows fatigue striation.
138
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 - Fatigue Striation

+6 more from this case →

ML00149 — Vibration Induced Fatigue in a Gas PipingM - Low Carbon SteelP - Piping spoolAp - FPSOCd - Vibration Induced Fatigue
Aspect by dye check of the upper side of the pipe, at the margin of the weld between the main pipe and the lateral branch, presenting a fatigue cracking initiated at the external side, probably induced by vibration.
68
VIEW
ML00149 / Dec.2018
Vibration Induced Fatigue in a Gas Piping
M - Low Carbon SteelP - Piping spoolAp - FPSOCd - Vibration Induced Fatigue
Cm - Aspect by NDTDf - Cracking
Aspect by dye check of the internal side of the 8" pipe, at the hole of the 2" lateral branch line, presenting the through thickness cracking initiated by fatigue at the external side, probably induced by vibration.
57
VIEW
ML00149 / Dec.2018
Vibration Induced Fatigue in a Gas Piping
M - Low Carbon SteelP - Piping spoolAp - FPSOCd - Vibration Induced Fatigue
Cm - Aspect by NDTDf - Through Wall Cracking
Aspect by dye check of the upper side of the pipe, external, at the weld between the 8" main pipe and the 2" lateral branch, presenting a fatigue cracking initiated at the weld margin and propagating into the base metal in a longitudinal direction.
55
VIEW
ML00149 / Dec.2018
Vibration Induced Fatigue in a Gas Piping
M - Low Carbon SteelP - Piping spoolAp - FPSOCd - Vibration Induced Fatigue
Cm - Aspect by NDTDf - Cracks
Macrography of the 8" pipe, welded to a 2" fitting (weldolet), welded to a 2" flange. The branch line was operating in this position (horizontal line with a lateral branch) and the through thickness fatigue crack is associated to the margin of the weld in the upper part of the pipe.
50
VIEW
ML00149 / Dec.2018
Vibration Induced Fatigue in a Gas Piping
M - Low Carbon SteelP - Piping spoolAp - FPSOCd - Vibration Induced Fatigue
Cm - NItal Etched MacroDf - Cracking
Macrography of a section tranverse to the pipe and to the weld between the 8"pipe and the 2" fitting weldolet. The crack starts exactly at the margin of the weld, in a geometric stress concentration raiser, in a position where it growths in the pipe longitudinal direction, and propagates in a straight line, not related to any metallurgical aspect.
41
VIEW
ML00149 / Dec.2018
Vibration Induced Fatigue in a Gas Piping
M - Low Carbon SteelP - Piping spoolAp - FPSOCd - Vibration Induced Fatigue
Cm - NItal Etched MacroDf - Margin of the Weld Crack

+7 more from this case →

ML00130 — Fatigue Fracture of Overloaded BoltsM - Low Alloy Medium Carbon QTP - FastenerAp - O&G Well DrillingCd - Mechanical Fatigue
Macroscopic aspect of the bolt fracture. Part of it is flat from the bottom of the thread.
166
VIEW
ML00130 / Jun.2018
Fatigue Fracture of Overloaded Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - O&G Well DrillingCd - Mechanical Fatigue
Cm - Aspect Before AnalysisDf - Fracture
Aspect of the fracture surface by scanning electron microscopy, presenting fatigue striations micromechanism. The bolt is a medium strength low alloy steel, medium carbon, quenched and tempered.
153
VIEW
ML00130 / Jun.2018
Fatigue Fracture of Overloaded Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - O&G Well DrillingCd - Mechanical Fatigue
Cm - Fractography by SEMDf - Fatigue Fracture
Detailed fractographic aspect of the flat part of the bolt fracture, presenting fatigue striations. The bolt is a medium strength low alloy steel, medium carbon, quenched and tempered.
141
VIEW
ML00130 / Jun.2018
Fatigue Fracture of Overloaded Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - O&G Well DrillingCd - Mechanical Fatigue
Cm - Fractography by SEMDf - Fatigue Fracture
Fractographic detailed aspect of the rough part of the fracture surface, presenting ductile dimples. This is the final fracture, by overload.
137
VIEW
ML00130 / Jun.2018
Fatigue Fracture of Overloaded Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - O&G Well DrillingCd - Mechanical Fatigue
Cm - Fractography by SEMDf - Ductile Fracture
Micrography of a longitudinal section, at the fillet that was tightened (to the end of the bolt) adjacent to the fracture. The cracking is typical of localized overloading, probably because it was only partially tightened in the tapped hole.
103
VIEW
ML00130 / Jun.2018
Fatigue Fracture of Overloaded Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - O&G Well DrillingCd - Mechanical Fatigue
Cm - Nital Etched Micrography by OMDf - Crack

+1 more from this case →

ML00119 — Thermal Fatigue of a Marine BoilerM - Low Carbon SteelP - Fabrication WeldAp - ShipCd - Thermal Fatigue
Micrography of the section transverse to the weld, presenting one crack at the edge of the tube. This is not the best direction of analysis because the cracks are parallel to the analyzed section. It is possible to see the crack from the surface, large and filled with oxides.
78
VIEW
ML00119 / Feb.2018
Thermal Fatigue of a Marine Boiler
M - Low Carbon SteelP - Fabrication WeldAp - ShipCd - Thermal Fatigue
Cm - Nital Etched Micrography by OMDf - Cracks
Micrographic detail of the crack at the edge of the tube. This is not the best direction of analysis because the cracks are parallel to the analyzed section. It is possible to see the crack from the surface, large and filled with oxides.
75
VIEW
ML00119 / Feb.2018
Thermal Fatigue of a Marine Boiler
M - Low Carbon SteelP - Fabrication WeldAp - ShipCd - Thermal Fatigue
Cm - Nital Etched Micrography by OMDf - Transgranular Cracking
Higher magnification macrography (in a stereoscope) of the surface exposed to the combustion chamber, presenting multiple cracks perpendicular to the internal diamater of the tube (left side of the figure). The cracks are located in the tube and propagated into the tube wall and welded joint.
75
VIEW
ML00119 / Feb.2018
Thermal Fatigue of a Marine Boiler
M - Low Carbon SteelP - Fabrication WeldAp - ShipCd - Thermal Fatigue
Cm - Surface AspectDf - Thermal Fatigue Cracks
Micrography of the cracking surface, presenting multiple cracks from the edge of the tube, typical of fatigue induced by stresses generated by differential expansion of the pipe in relation to the tubesheet, due to thermal cycles.
71
VIEW
ML00119 / Feb.2018
Thermal Fatigue of a Marine Boiler
M - Low Carbon SteelP - Fabrication WeldAp - ShipCd - Thermal Fatigue
Cm - Nital Etched Micrography by OMDf - Multiple cracks
Micrography of the cracking surface, presenting multiple cracks from the edge of the tube, typical of fatigue induced by stresses generated by differential expansion of the pipe in relation to the tubesheet, due to thermal cycles.
60
VIEW
ML00119 / Feb.2018
Thermal Fatigue of a Marine Boiler
M - Low Carbon SteelP - Fabrication WeldAp - ShipCd - Thermal Fatigue
Cm - Nital Etched Micrography by OMDf - Thermal Fatigue Cracks
ML00104 — Thermal Fatigue of a Boiler TubeM - Low Carbon SteelP - Autogenously Welded TubeAp - BoilerCd - Thermal Fatigue
Micrographic details of the longitudinal section of the tube, close to OD, showing paralel cracks, filled with oxides, perpendicular to the surface.
115
VIEW
ML00104 / Dec.2017
Thermal Fatigue of a Boiler Tube
M - Low Carbon SteelP - Autogenously Welded TubeAp - BoilerCd - Thermal Fatigue
Cm - As polished micrographyDf - Cracks Transverse to the Surface
Micrographic details of the longitudinal section of the tube, close to OD, showing paralel cracks, filled with oxides, perpendicular to the surface.
109
VIEW
ML00104 / Dec.2017
Thermal Fatigue of a Boiler Tube
M - Low Carbon SteelP - Autogenously Welded TubeAp - BoilerCd - Thermal Fatigue
Cm - As polished micrographyDf - Thermal Fatigue Cracks
Micrographic details of the longitudinal section of the tube, close to ID, showing paralel cracks, filled with oxides, perpendicular to the surface.
103
VIEW
ML00104 / Dec.2017
Thermal Fatigue of a Boiler Tube
M - Low Carbon SteelP - Autogenously Welded TubeAp - BoilerCd - Thermal Fatigue
Cm - As polished micrographyDf - Cracks Transverse to the Surface
Micrographic details of the longitudinal section of the tube, close to ID, showing paralel cracks, filled with oxides, perpendicular to the surface.
99
VIEW
ML00104 / Dec.2017
Thermal Fatigue of a Boiler Tube
M - Low Carbon SteelP - Autogenously Welded TubeAp - BoilerCd - Thermal Fatigue
Cm - As polished micrographyDf - Thermal Fatigue Cracks
Micrography of the longitudinal section of the tube, close to OD, showing the cracks from the surface. The cracks are filled with oxides and slightly opened by corrosion.
84
VIEW
ML00104 / Dec.2017
Thermal Fatigue of a Boiler Tube
M - Low Carbon SteelP - Autogenously Welded TubeAp - BoilerCd - Thermal Fatigue
Cm - Nital Etched Micrography by OMDf - Thermal Fatigue Cracks

+1 more from this case →

ML00050 — Fatigue Failure of a 316SS Pressure StabilizerM - Austenitic Stainless SteelP - Fabrication WeldAp - Chemical IndustryCd - Mechanical Fatigue
Aspect of the equipment presenting a through wall cracking at the margin of the fillet weld.
142
VIEW
ML00050 / Nov.2017
Fatigue Failure of a 316SS Pressure Stabilizer
M - Austenitic Stainless SteelP - Fabrication WeldAp - Chemical IndustryCd - Mechanical Fatigue
Cm - Aspect Before AnalysisDf - Cracking
The macrography of a transverse section of the shell to flange weld (Lepto's etch) shows that the cracking occurred through the shell plate thickness, at the margin of the fillet weld.
93
VIEW
ML00050 / Nov.2017
Fatigue Failure of a 316SS Pressure Stabilizer
M - Austenitic Stainless SteelP - Fabrication WeldAp - Chemical IndustryCd - Mechanical Fatigue
Cm - Transverse Section AspectDf - Cracking
Fracture surface after opening the shell cracking, presenting fatigue striation. The fracture presents also foreign particles.
132
VIEW
ML00050 / Nov.2017
Fatigue Failure of a 316SS Pressure Stabilizer
M - Austenitic Stainless SteelP - Fabrication WeldAp - Chemical IndustryCd - Mechanical Fatigue
Cm - Fractography by SEMDf - Fatigue Striation