Damage

3 cases · 35 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Condition: Fatigue Standard: AISI clear all

Damage — sub-branches

Crack 6Fatigue Crack 11Fatigue Fracture 3Fatigue Striation 4Fracture 1Pitting 5Plastic Deformation 1Through Wall 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
Aspect of the internal surface of the 2" nominal diameter pipe, SCH 40, presenting a circumferential through wall cracking in the pipe, not associated to any of the welded joints. It is possible to see the cracking parallel to the two welded joints: the pipe to weldolet (left side of the figure); and the pipe to flange (right side of the figure).
64
VIEW
ML00012 / Aug.2017
Vibration Induced Fatigue in a 316/316L SS
M - Austenitic Stainless SteelP - Seamless PipeAp - OffshoreCd - Vibration Induced Fatigue
Cm - Aspect Before AnalysisDf - Through Wall Cracking

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 →

ML00012 — Vibration Induced Fatigue in a 316/316L SSM - Austenitic Stainless SteelP - Seamless PipeAp - OffshoreCd - Vibration Induced Fatigue
Aspect of the internal surface of the 2" nominal diameter pipe, SCH 40, presenting a circumferential through wall cracking in the pipe, not associated to any of the welded joints. It is possible to see the cracking parallel to the two welded joints: the pipe to weldolet (left side of the figure); and the pipe to flange (right side of the figure).
57
VIEW
ML00012 / Aug.2017
Vibration Induced Fatigue in a 316/316L SS
M - Austenitic Stainless SteelP - Seamless PipeAp - OffshoreCd - Vibration Induced Fatigue
Cm - Aspect Before AnalysisDf - Through Wall Cracking
After opening the cracking the fracture surface aspect evidences fatigue cracking propagation, starting from the external side (OD).
68
VIEW
ML00012 / Aug.2017
Vibration Induced Fatigue in a 316/316L SS
M - Austenitic Stainless SteelP - Seamless PipeAp - OffshoreCd - Vibration Induced Fatigue
Cm - Fracture Surface AspectDf - Fatigue Fracture
Micrography of a longitudinal section of the pipe (seamless), that shows the through wall cracking, straigth and not associated to any welded region or microstructural problem.
64
VIEW
ML00012 / Aug.2017
Vibration Induced Fatigue in a 316/316L SS
M - Austenitic Stainless SteelP - Seamless PipeAp - OffshoreCd - Vibration Induced Fatigue
Cm - Micrography by OM using A262 Method ADf - Through Wall Cracking
Micrography of the pipe in a longitudinal section, close to the external surface, showing a pit (adjacent to the through wall cracking). The corrosion spt is not associated to any microstructural feature.
61
VIEW
ML00012 / Aug.2017
Vibration Induced Fatigue in a 316/316L SS
M - Austenitic Stainless SteelP - Seamless PipeAp - OffshoreCd - Vibration Induced Fatigue
Cm - Micrography by OMDf - Pitting
Aspect of a micrographic sample by scanning electron microscopy showing the external pipe surface, in the bottom, the fracture at the left side of the figure and several spots of pitting corrosion from the external surface. The polished section (transverse to the fracture and in a longitudinal section of the pipe) shows the morphology of the pit , 0.2 mm depth. Original magnification 50x.
54
VIEW
ML00012 / Aug.2017
Vibration Induced Fatigue in a 316/316L SS
M - Austenitic Stainless SteelP - Seamless PipeAp - OffshoreCd - Vibration Induced Fatigue
Cm - Micrography by SEMDf - Pitting

+6 more from this case →