UNS

9 cases · 35 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

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
ML00170 / Sep.2020
MIC in Aluminum Brass Tubes
M - Aluminum BrassP - Seamless tubeAp - MaritimeCd - Preferential Dissolution
Cm - Surface Aspect by SEMDf - Corrosion
ML00155 / Jan.2020
Failure of a Prestressed Concrete Steel Strand
M - High Carbon SteelP - Wire RopeAp - StructureCd - Corrosion Fatigue
Cm - NItal Etched MacroDf - Corrosion
ML00137 / Mar.2021
Brittle Fracture of a 15-5 PH Valve Spring
M - Precipitation Hardened Stainless SteelP - SpringAp - Oil and GasCd - Brittle Behavior
Cm - Surface Aspect by SEMDf - Corrosion
Aspect of the CuZn platesheet where it is corroded (cooling medium side).  The (hot) air cooler uses treated seawater as the cooling medium and the corroded regions are associated to the regions in the heat exchanger of higher temperatures, and the leakage occurred in regions of contact of the platesheet to cooper alloy tubes.
1167
ML00125 / Mar.2018
Dezincification of a Cooler Tubesheet
M - BrassP - PlateAp - ShipCd - Preferential Dissolution
Cm - Aspect Before AnalysisDf - Corrosion
ML00124 / Feb.2018
MIC of a Martensitic Valve Ring
M - Martensitic Stainless SteelP - ForgingAp - EnergyCd - Brittle Behavior
Cm - As polished micrographyDf - Corrosion
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
Aspect of the rusted knife, before cleaning.
1195
ML00054 / Dec.2018
Cutlery Corrosion
M - Martensitic Stainless SteelP - Foodstuff ArticleAp - KitchenCd - Pitting Corrosion
Cm - Aspect Before AnalysisDf - Corrosion

More from these cases

ML00172 — Brittle Fracture of a LAS Valve SpringM - Low Alloy Medium Carbon QTP - SpringAp - Oil and GasCd - Brittle Fracture
ML00172 / Mar.2021
Brittle Fracture of a LAS Valve Spring
M - Low Alloy Medium Carbon QTP - SpringAp - Oil and GasCd - Brittle Fracture
Cm - Surface Aspect by SEMDf - Corrosion
ML00155 — Failure of a Prestressed Concrete Steel StrandM - High Carbon SteelP - Wire RopeAp - StructureCd - Corrosion Fatigue
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 - Corrosion
ML00155 / Jan.2020
Failure of a Prestressed Concrete Steel Strand
M - High Carbon SteelP - Wire RopeAp - StructureCd - Corrosion Fatigue
Cm - As polishedDf - Corrosion
ML00155 / Jan.2020
Failure of a Prestressed Concrete Steel Strand
M - High Carbon SteelP - Wire RopeAp - StructureCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - Corrosion
ML00155 / Jan.2020
Failure of a Prestressed Concrete Steel Strand
M - High Carbon SteelP - Wire RopeAp - StructureCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - Corrosion
ML00155 / Jan.2020
Failure of a Prestressed Concrete Steel Strand
M - High Carbon SteelP - Wire RopeAp - StructureCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - Corrosion

+6 more from this case →

ML00137 — Brittle Fracture of a 15-5 PH Valve SpringM - Precipitation Hardened Stainless SteelP - SpringAp - Oil and GasCd - Brittle Behavior
ML00137 / Mar.2021
Brittle Fracture of a 15-5 PH Valve Spring
M - Precipitation Hardened Stainless SteelP - SpringAp - Oil and GasCd - Brittle Behavior
Cm - Surface Aspect by SEMDf - Corrosion
ML00125 — Dezincification of a Cooler TubesheetM - BrassP - PlateAp - ShipCd - Preferential Dissolution
Aspect of the tubesheet after removal of the cooper alloy tubes and water cleaning. The corrosion is more intense in the regions of tube connection.
176
ML00125 / Mar.2018
Dezincification of a Cooler Tubesheet
M - BrassP - PlateAp - ShipCd - Preferential Dissolution
Cm - Surface AspectDf - Corrosion
Transverse section of the tubesheet, after removal of the tubes.  The seawater sie is to the top of the figure.  It is possible to see regions of localized corrosion close to the tube position and a red layer all through the plate surface.
182
ML00125 / Mar.2018
Dezincification of a Cooler Tubesheet
M - BrassP - PlateAp - ShipCd - Preferential Dissolution
Cm - Transverse Section AspectDf - Corrosion
Macrographic detail of the transverse section of the tubesheet at the cooper alloy tube position, after removal of the 5/8" tube.  The red layer at the top of the plate (exposed to the cooling medium - treated seawater) is a region of selective corrosion, dezincification.
169
ML00125 / Mar.2018
Dezincification of a Cooler Tubesheet
M - BrassP - PlateAp - ShipCd - Preferential Dissolution
Cm - Transverse Section AspectDf - Corrosion
ML00125 / Mar.2018
Dezincification of a Cooler Tubesheet
M - BrassP - PlateAp - ShipCd - Preferential Dissolution
Cm - Surface Aspect by SEMDf - Corrosion
ML00124 — MIC of a Martensitic Valve RingM - Martensitic Stainless SteelP - ForgingAp - EnergyCd - Brittle Behavior
ML00124 / Feb.2018
MIC of a Martensitic Valve Ring
M - Martensitic Stainless SteelP - ForgingAp - EnergyCd - Brittle Behavior
Cm - As polished micrographyDf - Corrosion
ML00122 — Crevice Corrosion in a Subsea SystemM - Austenitic Stainless SteelP - CaseAp - Oil and GasCd - Crevice
After a longitudinal cut of the case it was possible to see that a localized corrosion has occurred associated to the regions where there were sealed holes, plugged, in a crevice condition, not related to any welded position.
193
ML00122 / Feb.2018
Crevice Corrosion in a Subsea System
M - Austenitic Stainless SteelP - CaseAp - Oil and GasCd - Crevice
Cm - Transverse Section AspectDf - Corrosion
Macrography of the longitudinal section of the case, that was welded to padeyes. The corrosion occurred in a region where there were no microstructural changes, only the hole that was sealed with a plug and suffered a crevice corrosion mechanism.
145
ML00122 / Feb.2018
Crevice Corrosion in a Subsea System
M - Austenitic Stainless SteelP - CaseAp - Oil and GasCd - Crevice
Cm - Macro Oxalic Acid Electrolytic EtchedDf - Corrosion
The macrography of a longitudinal section of the case shows one region where a through wall localized corrosion has occurred (in the left side of the image) and regions where the case was welded to a padeye, without any corrosion damage.
141
ML00122 / Feb.2018
Crevice Corrosion in a Subsea System
M - Austenitic Stainless SteelP - CaseAp - Oil and GasCd - Crevice
Cm - Macro Oxalic Acid Electrolytic EtchedDf - Corrosion
ML00054 — Cutlery CorrosionM - Martensitic Stainless SteelP - Foodstuff ArticleAp - KitchenCd - Pitting Corrosion
Detail of the rusted surface of the knife, before cleaning.
340
ML00054 / Dec.2018
Cutlery Corrosion
M - Martensitic Stainless SteelP - Foodstuff ArticleAp - KitchenCd - Pitting Corrosion
Cm - Surface AspectDf - Corrosion
Aspect of the rusted surface after cleaning, showing adhered products at the surface, in regions where the passive layer was destroyed and pitting corrosion occurred.
184
ML00054 / Dec.2018
Cutlery Corrosion
M - Martensitic Stainless SteelP - Foodstuff ArticleAp - KitchenCd - Pitting Corrosion
Cm - Surface Aspect by SEMDf - Corrosion
Detail of the rusted surface. EDS analysis inside the pitting shows a high Cl peak (the bright aspect inside the pitting), indicating that the salt over the surface was responsible for destroying the passive layer and the localized corrosion occurred.
172
ML00054 / Dec.2018
Cutlery Corrosion
M - Martensitic Stainless SteelP - Foodstuff ArticleAp - KitchenCd - Pitting Corrosion
Cm - Surface Aspect by SEMDf - Corrosion