Aspect Before Analysis

7 cases · 23 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Condition: Damage Microstructure: Segregation Bands clear all

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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
Aspect of the broken spring. The wire is 36 mm diameter and the ourter diameter of the spirals is 320 mm. It was broken in different locations.
434
VIEW
ML00172 / Mar.2021
Brittle Fracture of a LAS Valve Spring
M - Low Alloy Medium Carbon QTP - SpringAp - Oil and GasCd - Brittle Fracture
Cm - Aspect Before AnalysisDf - General View
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
Lateral image of a collapsed API 5D grade S135 drill pipe, presenting the fractured region (bottom of the figure) at the pipe body. Although the pipe steel is of a high strenght, the fracture characteristic is ductile, evidencing strong plastic deformation.
545
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 - General View
Aspect of the broken stud that was fastening a flanged line in a subsea body (tapped hole) using a nut. The fracture, transverse to the stud axis, occurred exactly at the body to flange interface. Adjacent to the fracture, all thread fillets (positioned inside the flange hole) presented cracks at the bottom of the thread. The stud was operating during seven years and was not corroded, indicating it was protected by the anodes. There are also deposits in the fillets suggesting the cathodic protection was effective even inside the flange hole.
799
VIEW
ML00136 / Jun.2018
Hydrogen Cracks of Subsea Studs
M - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Aspect Before AnalysisDf - General View
Aspect of the bolt fracture. The fracture appearance is irregular and there are several secondary cracks from thread fillets.
245
VIEW
ML00077 / Jun.2018
Hydrogen Cracking of LAS Subsea Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Aspect Before AnalysisDf - General View
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

More from these cases

ML00182 — Brittle Fracture of a LAS Fixing RodM - Low Alloy Medium Carbon QTP - StemAp - Mechanical IndustryCd - Brittle Fracture
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
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
Brittle Fracture of a LAS Fixing Rod
2
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 - Fracture
Brittle Fracture of a LAS Fixing Rod
5
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 - Fracture
Brittle Fracture of a LAS Fixing Rod
0
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 - Fracture
ML00172 — Brittle Fracture of a LAS Valve SpringM - Low Alloy Medium Carbon QTP - SpringAp - Oil and GasCd - Brittle Fracture
Aspect of the fracture of the spring. The spring surface shows shallow pits.
49
VIEW
ML00172 / Mar.2021
Brittle Fracture of a LAS Valve Spring
M - Low Alloy Medium Carbon QTP - SpringAp - Oil and GasCd - Brittle Fracture
Cm - Aspect Before AnalysisDf - Fracture
Surface to fracture interface. The spring shows corrosion and pits.
46
VIEW
ML00172 / Mar.2021
Brittle Fracture of a LAS Valve Spring
M - Low Alloy Medium Carbon QTP - SpringAp - Oil and GasCd - Brittle Fracture
Cm - Aspect Before AnalysisDf - Corrosion
Aspect of the flat fracture surfaces, brittle. The spring surface is corroded and presents pits.
31
VIEW
ML00172 / Mar.2021
Brittle Fracture of a LAS Valve Spring
M - Low Alloy Medium Carbon QTP - SpringAp - Oil and GasCd - Brittle Fracture
Cm - Aspect Before AnalysisDf - Brittle Fracture
Rusted aspect of the spring surface.
26
VIEW
ML00172 / Mar.2021
Brittle Fracture of a LAS Valve Spring
M - Low Alloy Medium Carbon QTP - SpringAp - Oil and GasCd - Brittle Fracture
Cm - Aspect Before AnalysisDf - General View
ML00162 — Valve Body Crack Growth from Weld DefectsM - Low Alloy Medium Carbon QTP - Valve BodyAp - O&G Well DrillingCd - Fatigue Induced by a Defect
The valve body cylindrical diameter is 6 5/8" and the actuator hole in the body is about 2" diameter. The crack is associated to the hole edge, propagating transverse to the body.
71
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 - General View
The figure illustrates the position of the ball and seats, as well as the valve actuator. The crack is located at the edge of the actuator hole, transverse to the cylindrical body.
63
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 - Longitudinal Section
ML00159 — Collapse of a Drill PipeM - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Ductile Behavior
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
ML00136 — Hydrogen Cracks of Subsea StudsM - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
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
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
ML00077 — Hydrogen Cracking of LAS Subsea BoltsM - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Aspect of the bolt surface with a detail of a secondary crack at the first thread fillet, close to the bolt head.
147
VIEW
ML00077 / Jun.2018
Hydrogen Cracking of LAS Subsea Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Aspect Before AnalysisDf - Secondary Cracks
Aspect of the bolt fracture. The fracture appearance is irregular.
137
VIEW
ML00077 / Jun.2018
Hydrogen Cracking of LAS Subsea Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Aspect Before AnalysisDf - Fracture