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85 cases · 399 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Capture method: Scanning Electron Microscope clear all

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Micrographic detail of the flange base metal presenting a coarse duplex ferritic austenitc structure and detrimental phases associated to the ferritic structure.
47
VIEW
ML00049 / Apr.2017
Pipe to Flange Welded Joint in a 14" ND Superduplex Spool
M - Super Duplex Stainless SteelP - Piping spoolAp - Oil and GasCd - Removed From Service
Cm - Electrolytic Etch Micrography by SEMDf - Duplex structure
Micrography of the blade, view inside the grain. The intragranular precipitation presents one unique size of precipitation, not yet coalesced, although the blade was in high temperature service for 50.000 hours. Etched by H2SO4 + HNO3 + H3PO4 reagent.
66
VIEW
ML00042 / Apr.2017
Gas Turbine Blade IN 939, Coated
M - NiCrCo AlloyP - CastAp - Gas TurbineCd - Intergranular Cracking
Cm - Micrography by SEMDf - Intragranular Secondary Precipitation
SEM fractograph at 1200x magnification showing an intergranular fracture surface with angular, faceted grains and fine feather-like markings.
86
VIEW
ML00041 / Jun.2017
Fatigue Fracture of Inconel 718 Spline Shaft
M - NiCrFe AlloyP - ShaftAp - Oil and GasCd - Vibration Induced Fatigue
Cm - Fractography by SEMDf - Fatigue Fracture
The fracture surface is flat, shows the graphite nodules and cleavage of the ferritic microstructure, indicating that the material have exceeded the capacity to acomodate the stress.
944
VIEW
ML00040 / Apr.2017
Brittle Fracture of a Valve Stem
M - Nodular Cast IronP - Valve StemAp - ShipCd - Brittle Fracture
Cm - Fractography by SEMDf - Cleavage Facets
External surface aspect of the flange showing preferential dissolution, responsible for nucleation of the through wall cracking.
245
VIEW
ML00002 / Jan.2018
Preferential Dissolution and Cracks in SDSS
M - Super Duplex Stainless SteelP - Fabrication WeldAp - PipingCd - Preferential Dissolution
Cm - Surface Aspect by SEMDf - Preferential Dissolution
Regions of the pin thread presenting pitting corrosion.
635
VIEW
ML00016 / Apr.2017
SCC in Free Cutting 303SS
M - Austenitic Stainless SteelP - Machined PartAp - OffshoreCd - Stress Corrosion
Cm - Surface Aspect by SEMDf - Localized Corrosion
The fracture surface of the main pipe is presented in low magnification (external pipe surface in the top) showing a flat propagation starting from the contour of the weld margin.
173
VIEW
ML00006 / Apr.2017
Vibration Induced Fatigue in 304SS
M - Austenitic Stainless SteelP - Longitudinal Seam Welded PipeAp - PipingCd - Vibration Induced Fatigue
Cm - Fractography by SEMDf - Margin of the Weld Crack
Martensitic structure at the cutting HAZ. Longitudinal section.
32
VIEW
ML00033 / Jan.2017
Plasma Cut of 1 1/4" Steel Plate
M - High Strength Low AlloyP - Rolled PlateAp - StructureCd - Cutting
Cm - Nital Etched Micrography by SEMDf - Martensite

More from these cases

ML00049 — Pipe to Flange Welded Joint in a 14" ND Superduplex SpoolM - Super Duplex Stainless SteelP - Piping spoolAp - Oil and GasCd - Removed From Service
Micrographic detail of the flange base metal presenting a coarse duplex ferritic austenitc structure and detrimental phases associated to the ferritic structure.
39
VIEW
ML00049 / Apr.2017
Pipe to Flange Welded Joint in a 14" ND Superduplex Spool
M - Super Duplex Stainless SteelP - Piping spoolAp - Oil and GasCd - Removed From Service
Cm - Electrolytic Etch Micrography by SEMDf - Duplex structure
ML00042 — Gas Turbine Blade IN 939, CoatedM - NiCrCo AlloyP - CastAp - Gas TurbineCd - Intergranular Cracking
Micrographic detail of the diffusion coating. H2SO4 + HNO3 + H3PO4 etched.
47
VIEW
ML00042 / Apr.2017
Gas Turbine Blade IN 939, Coated
M - NiCrCo AlloyP - CastAp - Gas TurbineCd - Intergranular Cracking
Cm - Micrography by SEMDf - Coating
ML00041 — Fatigue Fracture of Inconel 718 Spline ShaftM - NiCrFe AlloyP - ShaftAp - Oil and GasCd - Vibration Induced Fatigue
Microscopic detail of the transgranular striation in the fracture surface.
78
VIEW
ML00041 / Jun.2017
Fatigue Fracture of Inconel 718 Spline Shaft
M - NiCrFe AlloyP - ShaftAp - Oil and GasCd - Vibration Induced Fatigue
Cm - Fractography by SEMDf - Fatigue Fracture
ML00040 — Brittle Fracture of a Valve StemM - Nodular Cast IronP - Valve StemAp - ShipCd - Brittle Fracture
Detail of the cleavage micromechanism.
195
VIEW
ML00040 / Apr.2017
Brittle Fracture of a Valve Stem
M - Nodular Cast IronP - Valve StemAp - ShipCd - Brittle Fracture
Cm - Fractography by SEMDf - Cleavage Facets
ML00002 — Preferential Dissolution and Cracks in SDSSM - Super Duplex Stainless SteelP - Fabrication WeldAp - PipingCd - Preferential Dissolution
Detail of the region at the flange external surface where the material is suffering the preferential corrosion.
177
VIEW
ML00002 / Jan.2018
Preferential Dissolution and Cracks in SDSS
M - Super Duplex Stainless SteelP - Fabrication WeldAp - PipingCd - Preferential Dissolution
Cm - Surface Aspect by SEMDf - Preferential Dissolution
Micrographic detail of the through wall cracking in the middle of the thickness, showing that the cracking is associated to ferrite network in the (super)duplex microstructure.
128
VIEW
ML00002 / Jan.2018
Preferential Dissolution and Cracks in SDSS
M - Super Duplex Stainless SteelP - Fabrication WeldAp - PipingCd - Preferential Dissolution
Cm - Micrography by SEMDf - Crack
Micrographic detail of the cracking, associated to the ferrite network, that presents both corrosion (preferential dissolution) and fracture (clevage) aspects.
128
VIEW
ML00002 / Jan.2018
Preferential Dissolution and Cracks in SDSS
M - Super Duplex Stainless SteelP - Fabrication WeldAp - PipingCd - Preferential Dissolution
Cm - Electrolytic Etch Micrography by SEMDf - Crack
The fracture surface, although presenting a large amount of corrosion products, shows also evidences of a brittle behavior with regions of cleavage micromechanism.
116
VIEW
ML00002 / Jan.2018
Preferential Dissolution and Cracks in SDSS
M - Super Duplex Stainless SteelP - Fabrication WeldAp - PipingCd - Preferential Dissolution
Cm - Fractography by SEMDf - Cleavage Facets
Micrographic detail of the ferrite network with evidences of precipitation/formation of detrimental phases. NaOH solution was adopted for the electrolytic etching.
86
VIEW
ML00002 / Jan.2018
Preferential Dissolution and Cracks in SDSS
M - Super Duplex Stainless SteelP - Fabrication WeldAp - PipingCd - Preferential Dissolution
Cm - Electrolytic Etch Micrography by SEMDf - Delta ferrite

+2 more from this case →

ML00016 — SCC in Free Cutting 303SSM - Austenitic Stainless SteelP - Machined PartAp - OffshoreCd - Stress Corrosion
Regions of the localized corrosion spots associated to non metallic inclusions.
123
VIEW
ML00016 / Apr.2017
SCC in Free Cutting 303SS
M - Austenitic Stainless SteelP - Machined PartAp - OffshoreCd - Stress Corrosion
Cm - Surface Aspect by SEMDf - Non Metallic Inclusions
Detail of the pin surface showing that the material easily cracks because it presents regions of localized corrosion.
45
VIEW
ML00016 / Apr.2017
SCC in Free Cutting 303SS
M - Austenitic Stainless SteelP - Machined PartAp - OffshoreCd - Stress Corrosion
Cm - Surface Aspect by SEMDf - Fracture
ML00006 — Vibration Induced Fatigue in 304SSM - Austenitic Stainless SteelP - Longitudinal Seam Welded PipeAp - PipingCd - Vibration Induced Fatigue
Fracture surface micromechanism by striation, evidence of FATIGUE.
158
VIEW
ML00006 / Apr.2017
Vibration Induced Fatigue in 304SS
M - Austenitic Stainless SteelP - Longitudinal Seam Welded PipeAp - PipingCd - Vibration Induced Fatigue
Cm - Fractography by SEMDf - Fatigue Striation
Fracture surface micromechanism by striation, evidence of FATIGUE.
147
VIEW
ML00006 / Apr.2017
Vibration Induced Fatigue in 304SS
M - Austenitic Stainless SteelP - Longitudinal Seam Welded PipeAp - PipingCd - Vibration Induced Fatigue
Cm - Fractography by SEMDf - Fatigue Striation
ML00033 — Plasma Cut of 1 1/4" Steel PlateM - High Strength Low AlloyP - Rolled PlateAp - StructureCd - Cutting
Intercritical heating at 0.5 mm from the cut surface, showing martensitic islands.
27
VIEW
ML00033 / Jan.2017
Plasma Cut of 1 1/4" Steel Plate
M - High Strength Low AlloyP - Rolled PlateAp - StructureCd - Cutting
Cm - Nital Etched Micrography by SEMDf - Heat Affected Zone