Atlas

118 cases · 287 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Aspect of a crevice corrosion of the flange, under the bolt head, showing evidences that the cathodic protection system was not connected to the stainless steel instrument.
1434
ML00122 / Feb.2018
Crevice Corrosion in a Subsea System
M - Austenitic Stainless SteelP - CaseAp - Oil and GasCd - Crevice
Cm - Aspect Before AnalysisDf - Localized Corrosion
Aspect of the Nitronic 60 cylinder, OD 36.4mm, presenting pits at the external surface.
219
ML00121 / Feb.2018
Pitting Corrosion in a Subsea System
M - Austenitic / MartensiticP - Rod & CylinderAp - SubseaCd - Pitting Corrosion
Cm - Aspect Before AnalysisDf - External Surface
Detailed aspect of the eye bolt fracture position, with strong plastic deformation indicating ductile overloading. The red marks in the thread surface of the bolt (in the left side of the image) correspond to the position where the nut was tight. Thread fillets adjacent to the fracture presented secondary cracks.
1125
ML00120 / Jun.2018
Ductile Rupture of a Carbon Steel Eye Bolt
M - Low Carbon SteelP - FastenerAp - AutomotiveCd - Overload
Cm - Aspect Before AnalysisDf - Ductile Fracture
The welded joint of the flat position is shown from the root side.  It is possible to see that the use of the backing generated the possibility for melting the base metal out of the groove, without detection of this condition during welding, responsible for creating defects and avoiding the WPS qualification.
102
ML00118 / Jan.2018
Non qualified GMAW of Aluminum Plates
M - Aluminum Magnesium ManganeseP - Welded Testpiece for QualificationAp - ShipCd - Non qualified
Cm - Aspect Before AnalysisDf - General View
Shaft pinion presenting the bearing surface, with machining markes, from where the thermal spray layer was detached.  The diameter of the 880 mm long shaft in this region is about 75 mm.
426
ML00108 / Dec.2017
Thermal Spray Layer in a Pinion Shaft
M - High Strength Low AlloyP - ShaftAp - EngineCd - Coating Defect
Cm - Aspect Before AnalysisDf - General View
Aspect of the superheater ND 1" tube that was in operation for about 35,000 hours and presented a thick deposit at the external surface.
211
ML00107 / Dec.2017
Carburized 9Cr1MoV Superheater Tube
M - Heat Resistant SteelP - Seamless tubeAp - BoilerCd - Carburization
Cm - Aspect Before AnalysisDf - General View
ML00106 / Dec.2017
Inconel 718 Submarine Bolt
M - NiCrFe AlloyP - BoltAp - SubseaCd - Typical manufacturing
Cm - Aspect Before AnalysisDf - General View
Aspect of the bolt with a special head, to be adopted in subsea condition. M12, 1/2" 13UNC.
342
ML00105 / Jun.2018
Inconel 718 Bolt of Special Head
M - NiCrFe AlloyP - FastenerAp - SubseaCd - Typical manufacturing
Cm - Aspect Before AnalysisDf - General View

More from these cases

ML00122 — Crevice Corrosion in a Subsea SystemM - Austenitic Stainless SteelP - CaseAp - Oil and GasCd - Crevice
Flanged case, 640mm long.  The photo presents a general view of the instrumentation system, destroyed after only 6 months in subsea service.  The system was manufactured using only 316 stainless steel and the case was 20 mm thick.
335
ML00122 / Feb.2018
Crevice Corrosion in a Subsea System
M - Austenitic Stainless SteelP - CaseAp - Oil and GasCd - Crevice
Cm - Aspect Before AnalysisDf - General View
Aspect of the instrument system after disassembling.  The internal part of the case, where the electronic device was operating, was wet by seawater and failed to send signals to the surface.
258
ML00122 / Feb.2018
Crevice Corrosion in a Subsea System
M - Austenitic Stainless SteelP - CaseAp - Oil and GasCd - Crevice
Cm - Aspect Before AnalysisDf - General View
Detail of the electronic device after removing the external case.  It is corroded because seawater entered in the equipment that was pressurized from the external sea environment.
228
ML00122 / Feb.2018
Crevice Corrosion in a Subsea System
M - Austenitic Stainless SteelP - CaseAp - Oil and GasCd - Crevice
Cm - Aspect Before AnalysisDf - Corrosion
The case where the electronic device was installed suffered a localized corrosion that allowed the seawater to wet the internal side, destroying it. The position where the leakage occurred originally presented a hole that was sealed with a plug and the corrosion occurred in a crevice condition.
166
ML00122 / Feb.2018
Crevice Corrosion in a Subsea System
M - Austenitic Stainless SteelP - CaseAp - Oil and GasCd - Crevice
Cm - Aspect Before AnalysisDf - Localized Corrosion
ML00121 — Pitting Corrosion in a Subsea SystemM - Austenitic / MartensiticP - Rod & CylinderAp - SubseaCd - Pitting Corrosion
Aspect of the 17-4 PH rod, OD 10.6 mm, presenting deep pits at the external surface.
125
ML00121 / Feb.2018
Pitting Corrosion in a Subsea System
M - Austenitic / MartensiticP - Rod & CylinderAp - SubseaCd - Pitting Corrosion
Cm - Aspect Before AnalysisDf - External Surface
ML00120 — Ductile Rupture of a Carbon Steel Eye BoltM - Low Carbon SteelP - FastenerAp - AutomotiveCd - Overload
Apect of the 1/2" ND bumper eye bolt that was fractured (in the left side of the figure) in the position where the nut was tight.
192
ML00120 / Jun.2018
Ductile Rupture of a Carbon Steel Eye Bolt
M - Low Carbon SteelP - FastenerAp - AutomotiveCd - Overload
Cm - Aspect Before AnalysisDf - General View
ML00118 — Non qualified GMAW of Aluminum PlatesM - Aluminum Magnesium ManganeseP - Welded Testpiece for QualificationAp - ShipCd - Non qualified
The welded joint of the vertical up position is shown from the root side.  It is possible to see that the use of the backing generated the possibility for melting the base metal out of the groove, without detection of this condition during welding, responsible for creating defects and avoiding the WPS qualification.
122
ML00118 / Jan.2018
Non qualified GMAW of Aluminum Plates
M - Aluminum Magnesium ManganeseP - Welded Testpiece for QualificationAp - ShipCd - Non qualified
Cm - Aspect Before AnalysisDf - General View
ML00108 — Thermal Spray Layer in a Pinion ShaftM - High Strength Low AlloyP - ShaftAp - EngineCd - Coating Defect
ML00108 / Dec.2017
Thermal Spray Layer in a Pinion Shaft
M - High Strength Low AlloyP - ShaftAp - EngineCd - Coating Defect
Cm - Aspect Before AnalysisDf - Layer Detachment