Ferritic Bainitic

5 cases · 19 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Standard: ASTM Capture method: Optical Microscope Detail focus: Damage clear all

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Micrography of the thread at the valve body surface, showing localized dissolution of the thread.
73
VIEW
ML00184 / Apr.2023
Dissimilar Steels in a Threaded Connection
M - Low Carbon SteelP - ForgingAp - OffshoreCd - Localized Dissolution
Cm - Nital Etched Micrography by OMDf - Corroded Thread
WELD METAL SURFACE
43
VIEW
ML00177 / Dec.2021
Cr-Mo Seam Welded Tube
M - CrMo SteelP - Longitudinally Seam WeldedAp - Fired HeaterCd - Not according to spec
Cm - Nital Etched Micrography by OMDf - Segregated Regions
Micrographic detail of the forging lap defect that appears at the nut surface like a crack, filled with oxides. The nut presented a martensitic structure in the center of the nut, but in the regions adjacent to the defect the structure is ferritic-bainitic due to decarburization. There are several globular oxides (grey spots) that became entrapped during the forging.
654
VIEW
ML00099 / Jan.2018
Forging Defect in a Cadmium Plated Nut
M - Medium Carbon SteelP - NutAp - PipingCd - Fabrication Defect
Cm - Nital Etched Micrography by OMDf - Crack
The micrographic aspect of the cracks in a section transverse to the weld (the removed sample), shows that there are cracks with different sizes, the larger are filled with products that indicate they were opened for longer times.
67
VIEW
ML00071 / Jan.2019
Reheating Cracking of a CrMo Vessel Weld
M - CrMo SteelP - In Field WeldAp - EnergyCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Intergranular Cracking
Cold cracking of the fillet weld adopted to attach a flat support into a vessel shell in the internal side, using an unsuitable welding procedure that created a too high hardness HAZ.
123
VIEW
ML00008 / Nov.2017
Cold Cracks in CMn Steel Pressure Vessel
M - CMn SteelP - In Field WeldAp - BoilerCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Cracks

More from these cases

ML00184 — Dissimilar Steels in a Threaded ConnectionM - Low Carbon SteelP - ForgingAp - OffshoreCd - Localized Dissolution
Micrography of the valve body carbon steel thread, in the peak. Ferritic-bainitic structure.
64
VIEW
ML00184 / Apr.2023
Dissimilar Steels in a Threaded Connection
M - Low Carbon SteelP - ForgingAp - OffshoreCd - Localized Dissolution
Cm - Nital Etched Micrography by OMDf - Corroded Thread
Micrographic detail of the valve body carbon steel thread, in the peak. Ferritic-bainitic structure.
55
VIEW
ML00184 / Apr.2023
Dissimilar Steels in a Threaded Connection
M - Low Carbon SteelP - ForgingAp - OffshoreCd - Localized Dissolution
Cm - Nital Etched Micrography by OMDf - Corroded Thread
Cross-section near a threaded surface showing an acicular matrix structure bordered by a dark, layered corrosion/oxide band along the thread root.
1
VIEW
ML00184 / Apr.2023
Dissimilar Steels in a Threaded Connection
M - Low Carbon SteelP - ForgingAp - OffshoreCd - Localized Dissolution
Cm - Nital Etched Micrography by OMDf - Oxide Layer
ML00177 — Cr-Mo Seam Welded TubeM - CrMo SteelP - Longitudinally Seam WeldedAp - Fired HeaterCd - Not according to spec
WELD METAL T/2
31
VIEW
ML00177 / Dec.2021
Cr-Mo Seam Welded Tube
M - CrMo SteelP - Longitudinally Seam WeldedAp - Fired HeaterCd - Not according to spec
Cm - Nital Etched Micrography by OMDf - Segregated Regions
ML00099 — Forging Defect in a Cadmium Plated NutM - Medium Carbon SteelP - NutAp - PipingCd - Fabrication Defect
Micrography of the nut in a section transverse to the surface indication. There are several microcracks (parallel and perpendicular to the nut surface) filled with oxides. The nut presented a martensitic microstructure in the center of the thickness and a ferritic-bainitic microstructure at surface and adjacent to the defect, due to decarburization occurred during high temperature forging.
130
VIEW
ML00099 / Jan.2018
Forging Defect in a Cadmium Plated Nut
M - Medium Carbon SteelP - NutAp - PipingCd - Fabrication Defect
Cm - Nital Etched Micrography by OMDf - Crack
Micrographic detail of the lap at the nut surface, as polished. The 20 microns cadmium layer is evident, penetrating in the lap.
46
VIEW
ML00099 / Jan.2018
Forging Defect in a Cadmium Plated Nut
M - Medium Carbon SteelP - NutAp - PipingCd - Fabrication Defect
Cm - As polished micrographyDf - Lap
ML00071 — Reheating Cracking of a CrMo Vessel WeldM - CrMo SteelP - In Field WeldAp - EnergyCd - Welding Defect
Micrographic aspect of opened cracks, filled with oxides.
63
VIEW
ML00071 / Jan.2019
Reheating Cracking of a CrMo Vessel Weld
M - CrMo SteelP - In Field WeldAp - EnergyCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Cracks
Micrographic details of opened cracks, filled with oxides.
56
VIEW
ML00071 / Jan.2019
Reheating Cracking of a CrMo Vessel Weld
M - CrMo SteelP - In Field WeldAp - EnergyCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Cracks
Micrographic aspect of thin cracks.
59
VIEW
ML00071 / Jan.2019
Reheating Cracking of a CrMo Vessel Weld
M - CrMo SteelP - In Field WeldAp - EnergyCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Cracks
Micrographic details of thin cracks.
63
VIEW
ML00071 / Jan.2019
Reheating Cracking of a CrMo Vessel Weld
M - CrMo SteelP - In Field WeldAp - EnergyCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Cracks
ML00008 — Cold Cracks in CMn Steel Pressure VesselM - CMn SteelP - In Field WeldAp - BoilerCd - Welding Defect
Cold cracking of the fillet weld adopted to attach a flat support into a vessel shell in the internal side, using an unsuitable welding procedure that created a too high hardness HAZ. The cracks are mainly located at the fusion line.
118
VIEW
ML00008 / Nov.2017
Cold Cracks in CMn Steel Pressure Vessel
M - CMn SteelP - In Field WeldAp - BoilerCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Cracks
Cold cracking of the fillet weld adopted to attach a flat support into a vessel shell in the internal side, using an unsuitable welding procedure that created a too high hardness HAZ. Several internal cracks at the fusion line.
101
VIEW
ML00008 / Nov.2017
Cold Cracks in CMn Steel Pressure Vessel
M - CMn SteelP - In Field WeldAp - BoilerCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Cracks
Cold cracking of the fillet weld adopted to attach a flat support into a vessel shell using an unsuitable welding procedure, with a low preheating and no PWHT. Cracks propagated in the heat affected zone.
99
VIEW
ML00008 / Nov.2017
Cold Cracks in CMn Steel Pressure Vessel
M - CMn SteelP - In Field WeldAp - BoilerCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Cracks
Cold cracking of the fillet weld adopted to attach a flat support into a vessel shell using an unsuitable welding procedure, with a low preheating and no PWHT. Cracks propagated in the weld metal.
100
VIEW
ML00008 / Nov.2017
Cold Cracks in CMn Steel Pressure Vessel
M - CMn SteelP - In Field WeldAp - BoilerCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Cracks