Damage

5 cases · 18 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Product: Forging Capture method: Optical Microscope Detail focus: Sampling and Analysis clear all

Damage — sub-branches

Brittle Behavior 1Corrosion 3Fabrication Defect 2Hydrogen 1

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Micrography of the valve body carbon steel thread, in the valley. Ferritic-bainitic structure.
77
VIEW
ML00184 / Apr.2023
Dissimilar Steels in a Threaded Connection
M - Low Carbon SteelP - ForgingAp - OffshoreCd - Localized Dissolution
Cm - Nital Etched Micrography by OMDf - Transverse Section
Quenched and tempered structure of the F22 steel forging, presenting about 230HV10 average hardness.
133
VIEW
ML00178 / Jan.2022
Cold cracks in Cr-Mo Welded Forging
M - CrMo SteelP - ForgingAp - O&G Well DrillingCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Base Metal
Low magnification micrography of the valve at the welded joint of the body to the insert (fillet weld). The cracking was arrested at the position of this welded joint because the structures of the weld metal, insert and heat affected zones are tough (austenitic in the weld metal and insert, and free from sigma in the HAZ) .
48
VIEW
ML00134 / Aug.2020
Brittle Fracture of a Superduplex Valve Body
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Fracture
Cm - NaOH Electrolytic Etched MicroDf - Welded Joint
Micrography of the longitudinal section of the forging material, presenting a granular austenite, precipitation hardened.
84
VIEW
ML00078 / Jun.2017
Hydrogen Cracking of IN 718 Subsea Connector
M - NiCrFe AlloyP - ForgingAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Longitudinal Section
The liquation crack is a hot crack in the base metal (at the HAZ) that induces a solidification crack in the weld metal.
66
VIEW
ML00072 / Jan.2018
Liquation Cracks in a High Strength Joint
M - Low Alloy Medium Carbon QTP - Longitudinal Seam Welded PipeAp - O&G Well DrillingCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Weld Metal

More from these cases

ML00178 — Cold cracks in Cr-Mo Welded ForgingM - CrMo SteelP - ForgingAp - O&G Well DrillingCd - Welding Defect
Fusion line of the forging side, in the cap, showing the weld metal (to the top of the image) and the base metal (to the bottom of the image). The heat affected zone hardness is about 270HV10.
108
VIEW
ML00178 / Jan.2022
Cold cracks in Cr-Mo Welded Forging
M - CrMo SteelP - ForgingAp - O&G Well DrillingCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Heat Affected Zone
The columnar grains of the weld metal in the cap presented a martensitic structure.
60
VIEW
ML00178 / Jan.2022
Cold cracks in Cr-Mo Welded Forging
M - CrMo SteelP - ForgingAp - O&G Well DrillingCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Weld Metal
ML00134 — Brittle Fracture of a Superduplex Valve BodyM - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Fracture
Micrography of the valve at the welded joint of the body to the insert (fillet weld). The cracking was arrested at the position of this welded joint because the structures of the weld metal, insert and heat affected zones are tough (austenitic in the weld metal and insert, and free from sigma in the HAZ) .
46
VIEW
ML00134 / Aug.2020
Brittle Fracture of a Superduplex Valve Body
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Fracture
Cm - NaOH Electrolytic Etched MicroDf - Heat Affected Zone
Micrographic detail of the fusion line of the welded joint of the body to the insert (fillet weld). The cracking was arrested at the position of this welded joint because the structures of the weld metal, insert and heat affected zones are tough (austenitic in the weld metal and insert, and free from sigma in the HAZ) .
39
VIEW
ML00134 / Aug.2020
Brittle Fracture of a Superduplex Valve Body
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Fracture
Cm - NaOH Electrolytic Etched MicroDf - Heat Affected Zone
Micrography of the valve at the welded joint of the body to the insert (fillet weld). The heat affected zone shows that the sigma phase was removed, which means that the base metal was degradated and during welding the thermal cycle created a condition to remove the sigma phase (dissolve it).
38
VIEW
ML00134 / Aug.2020
Brittle Fracture of a Superduplex Valve Body
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Fracture
Cm - NaOH Electrolytic Etched MicroDf - Heat Affected Zone
Micrographic detail of the heat affected zone of the valve to the insert joint showing that the sigma phase was removed, which means that the base metal was degradated and during welding the thermal cycle created a condition to dissolve the sigma phase.
39
VIEW
ML00134 / Aug.2020
Brittle Fracture of a Superduplex Valve Body
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Fracture
Cm - NaOH Electrolytic Etched MicroDf - Heat Affected Zone
ML00072 — Liquation Cracks in a High Strength JointM - Low Alloy Medium Carbon QTP - Longitudinal Seam Welded PipeAp - O&G Well DrillingCd - Welding Defect
Micrographic detail of the cracks at the fusion line of the welded joint, at the connector side. The cracking presents morphology of melting regions of impurities at grain boundaries of the large grains of the heat affected zone (HAZ).
57
VIEW
ML00072 / Jan.2018
Liquation Cracks in a High Strength Joint
M - Low Alloy Medium Carbon QTP - Longitudinal Seam Welded PipeAp - O&G Well DrillingCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Fusion Line
Micrography of the AISI 4130 forging, 5/8" thickness, close to the welded region, in the longitudinal section.
42
VIEW
ML00072 / Jan.2018
Liquation Cracks in a High Strength Joint
M - Low Alloy Medium Carbon QTP - Longitudinal Seam Welded PipeAp - O&G Well DrillingCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Base Metal Left Side
Micrographic detail of the AISI 4130 forging, 5/8" thickness, close to the welded region, in the longitudinal section.
45
VIEW
ML00072 / Jan.2018
Liquation Cracks in a High Strength Joint
M - Low Alloy Medium Carbon QTP - Longitudinal Seam Welded PipeAp - O&G Well DrillingCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Base Metal Left Side
Micrography of the X65 pipe, 5/8" thickness, in the longitudinal section.
45
VIEW
ML00072 / Jan.2018
Liquation Cracks in a High Strength Joint
M - Low Alloy Medium Carbon QTP - Longitudinal Seam Welded PipeAp - O&G Well DrillingCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Base Metal Right Side
Micrographic detail of the X65 pipe, 5/8" thickness, in the longitudinal section.In the center of the pipe thickness there is a segregation band of bainitic structure. The cracking was not associated to the pipe but to the other side, the forged connector.
43
VIEW
ML00072 / Jan.2018
Liquation Cracks in a High Strength Joint
M - Low Alloy Medium Carbon QTP - Longitudinal Seam Welded PipeAp - O&G Well DrillingCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Base Metal Right Side

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