UNS

4 cases · 36 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Condition: Damage Microstructure: Ferritic Capture method: Optical Microscope clear all

UNS — sub-branches

G10050 1G10080 1G12110 1G15240 1K03101 1

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Micrography of the longitudinal section of the fitiing, in a free-cutting steel. The microstructure is predominantly ferritic and there is a large amount of sulfide inclusions, aligned perpendicular to the forming direction.
98
VIEW
ML00103 / Nov.2017
Brittle Fracture of a Free-Cutting Connector
M - Low Carbon SteelP - Machined PartAp - ShipCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Longitudinal Section
Micrography of the weld metal presenting a martensitic island with microcracks, due to a localized increase in the manganese and silicon content, probably because an active flux was adopted in a condition where a high cleanning action was not required. A high flux-to-wire ratio (>1) could also be an issue.
794
VIEW
ML00067 / May.2017
Cold Cracks in C-Mn SAW Weld Metal
M - CMn SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Microcracks
Micrography of the ferritic low carbon steel plate (8 mm superior plate).
80
VIEW
ML00069 / May.2017
Liquation Cracks in SAW of Low Carbon Steel
M - Low Carbon SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Base Metal
A small sample was removed from the steam drum and the micrography shows that the cracks are intergranular (previous austenite) and located in the weld metal.
285
VIEW
ML00020 / Apr.2017
Intergranular SCC in Boiler Steam Drum Repair
M - Low Carbon SteelP - Repair WeldAp - BoilerCd - Stress Corrosion
Cm - Nital Etched Micrography by OMDf - Corrosion Cracking

More from these cases

ML00103 — Brittle Fracture of a Free-Cutting ConnectorM - Low Carbon SteelP - Machined PartAp - ShipCd - Brittle Fracture
Micrographic detail of the longitudinal section of the fitiing, in a free-cutting steel. The microstructure is predominantly ferritic, with small perlitic areas and some free cementite at ferritic grain boundaries. There is a large amount of sulfide inclusions, aligned perpendicular to the forming direction.
107
VIEW
ML00103 / Nov.2017
Brittle Fracture of a Free-Cutting Connector
M - Low Carbon SteelP - Machined PartAp - ShipCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Non Metallic Inclusions
Micrography of the transerse section of the fitiing, in a free-cutting steel. The microstructure is predominantly ferritic and the inclusions appear as dots.
97
VIEW
ML00103 / Nov.2017
Brittle Fracture of a Free-Cutting Connector
M - Low Carbon SteelP - Machined PartAp - ShipCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Transverse Section
Micrographic detail of the transverse section of the fitiing, in a free-cutting steel. The microstructure is predominantly ferritic, some perlitic areas and free cementite at ferritic grain boundaries. There is a large amount of inclusions, that appear as spots.
82
VIEW
ML00103 / Nov.2017
Brittle Fracture of a Free-Cutting Connector
M - Low Carbon SteelP - Machined PartAp - ShipCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Predominantly Ferritic
The longitudinal section of the fitting at the thread shows plastic deformation of the fillets, and a crack at the bottom of the thread.
56
VIEW
ML00103 / Nov.2017
Brittle Fracture of a Free-Cutting Connector
M - Low Carbon SteelP - Machined PartAp - ShipCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Crack
Micrographic detail of the longitudinal section of the fitting at the thread, showing a crack at the bottom of the thread.
53
VIEW
ML00103 / Nov.2017
Brittle Fracture of a Free-Cutting Connector
M - Low Carbon SteelP - Machined PartAp - ShipCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Crack

+4 more from this case →

ML00067 — Cold Cracks in C-Mn SAW Weld MetalM - CMn SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Micrography of the 12 mm plate base metal, carbon-manganese steel. Ferritic-perlitic structure, refined.
58
VIEW
ML00067 / May.2017
Cold Cracks in C-Mn SAW Weld Metal
M - CMn SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Base Metal
Micrography of the 8 mm plate base metal, low carbon steel. Predominantly ferritic structure.
57
VIEW
ML00067 / May.2017
Cold Cracks in C-Mn SAW Weld Metal
M - CMn SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Base Metal
Micrography of the weld metal in the center of the fillet. Typical ferritic structure and typical low carbon chemistry.
50
VIEW
ML00067 / May.2017
Cold Cracks in C-Mn SAW Weld Metal
M - CMn SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Weld Metal
Micrography of the weld metal in a non cracked region. Ferritic weld metal presenting hardness level about 220 HV1.
44
VIEW
ML00067 / May.2017
Cold Cracks in C-Mn SAW Weld Metal
M - CMn SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Weld Metal
Micrographic detail of the weld metal in a non cracked region. Ferritic weld metal presenting hardness level about 220 HV1.
46
VIEW
ML00067 / May.2017
Cold Cracks in C-Mn SAW Weld Metal
M - CMn SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Weld Metal

+6 more from this case →

ML00069 — Liquation Cracks in SAW of Low Carbon SteelM - Low Carbon SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Micrographic detail of the ferritic low carbon steel plate (8 mm superior plate).
80
VIEW
ML00069 / May.2017
Liquation Cracks in SAW of Low Carbon Steel
M - Low Carbon SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Base Metal
Micrographic detail of the weld metal presenting a typical low carbon steel structure (acicular ferrite and previous austenite grain boundary ferrite).
78
VIEW
ML00069 / May.2017
Liquation Cracks in SAW of Low Carbon Steel
M - Low Carbon SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Weld Metal
Micrographic detail of the weld metal presenting a typical low carbon steel structure (acicular ferrite and previous austenite grain boundary ferrite).
72
VIEW
ML00069 / May.2017
Liquation Cracks in SAW of Low Carbon Steel
M - Low Carbon SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Weld Metal
Micrography of the fracture at the superior plate (8 mm thickness). The fracture occurred in the coarse grain heat affected zone.
60
VIEW
ML00069 / May.2017
Liquation Cracks in SAW of Low Carbon Steel
M - Low Carbon SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Fracture
Micrography of the fracture at the fillet weld margin. The fracture occurred in the coarse grain heat affected zone of the superior plate (8 mm thickness).
54
VIEW
ML00069 / May.2017
Liquation Cracks in SAW of Low Carbon Steel
M - Low Carbon SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Fracture

+3 more from this case →

ML00020 — Intergranular SCC in Boiler Steam Drum RepairM - Low Carbon SteelP - Repair WeldAp - BoilerCd - Stress Corrosion
The micrography of the small sample removed from the steam drum shows that the cracks are intergranular (previous austenite) and located in the weld metal.
274
VIEW
ML00020 / Apr.2017
Intergranular SCC in Boiler Steam Drum Repair
M - Low Carbon SteelP - Repair WeldAp - BoilerCd - Stress Corrosion
Cm - Nital Etched Micrography by OMDf - Corrosion Cracking
Secondary cracks in the weld metal showing an intergranular morphology. Stress Corrosion Cracking.
249
VIEW
ML00020 / Apr.2017
Intergranular SCC in Boiler Steam Drum Repair
M - Low Carbon SteelP - Repair WeldAp - BoilerCd - Stress Corrosion
Cm - Nital Etched Micrography by OMDf - Corrosion Cracking
Detail of the secondary cracks in the weld metal with intergranular morphology. Stress Corrosion Cracking.
251
VIEW
ML00020 / Apr.2017
Intergranular SCC in Boiler Steam Drum Repair
M - Low Carbon SteelP - Repair WeldAp - BoilerCd - Stress Corrosion
Cm - Nital Etched Micrography by OMDf - Corrosion Cracking
Detail of the intergranular stress corrosion cracking of the drum shell weld repair.
217
VIEW
ML00020 / Apr.2017
Intergranular SCC in Boiler Steam Drum Repair
M - Low Carbon SteelP - Repair WeldAp - BoilerCd - Stress Corrosion
Cm - Nital Etched Micrography by OMDf - Corrosion Cracking