Ferrous Alloys

94 cases · 225 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Capture method: Naked Eye or Stereoscope clear all

Ferrous Alloys — sub-branches

Carbon Steel 31Cast Iron 9High Alloy Steel 52Low Alloy Steel 56Tool Steel 2

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Fracture view presenting two diferente aspects, brittle in the bottom of the figure and in the center (most part of the fracture) and ductile in the top of the figure. Nominal diameter of the bolt 1 1/2".
203
VIEW
ML00074 / Jun.2018
Hydrogen Cracking of a 17-4 PH Subsea Bolt
M - Precipitation Hardened Stainless SteelP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Fracture Surface AspectDf - General View
The macrography of a longitudinal section of the pipe and connector, at the welded joint, shows that the welding was conducted from both side of the groove, starting from the ID and finishing from the OD, ID later machined flush. The cracking was detected by ultrasonic test and the macro shows that it is at the fusion line, growthing into the weld metal. See the schematic drawing in the next figure
535
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 MacroDf - Longitudinal Section
Image of the surface of the blade, after preparation and Kalling etch, revealing the welded joint between the original casting and the insert casting adopted in the remanufacture. See the schematic drawing in the next figure
341
VIEW
ML00055 / Apr.2017
CA6NM Blade Remanufactured by Welding
M - Martensitic Stainless SteelP - Remanufacture by WeldingAp - EnergyCd - Removed From Service
Cm - Surface AspectDf - Welded Joint
Macrosection transverse to the longitudinal seam weld, presenting the two passes, the first welded from the internal side and the second welded from the external side. It is possible to see the columnar grains of the weld and the heat affected zone (HAZ) from each pass. See the schematic drawing in the next figure
427
VIEW
ML00053 / Mar.2017
SAW Longitudinal Seam of X70 Pipe
M - Microalloyed SteelP - Longitudinal Seam Welded PipeAp - SubseaCd - Welding
Cm - NItal Etched MacroDf - Welded Joint
The macrography of a longitudinal section of the shell plate (sample removed from the boiler), at the position of the fillet weld (sealing weld) with a tube, where surface welding repairs created conditions for cracking the base material in a transgranular morphology. Several cracks were identify starting from the steam drum internal surface.
448
VIEW
ML00019 / Apr.2017
Transgranular SCC in Boiler Steam Drum
M - CMn SteelP - Rolled PlateAp - BoilerCd - Stress Corrosion
Cm - Transverse Section AspectDf - Cracks
Macrography of the typical welded joint between the superior plate (8mm) and the inferior plate (12 mm) using one SAW fillet. The superior plate is welded in the thickness and the inferior plate is welded at the surface in this overlap joint. See the schematic drawing in the next figure
95
VIEW
ML00069 / May.2017
Liquation Cracks in SAW of Low Carbon Steel
M - Low Carbon SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - NItal Etched MacroDf - Welded Joint
Macrography of the welded joint upper part. Transverse section showing the different zones studied in this ML. See the schematic drawing in the next image.
454
VIEW
ML00045 / Aug.2017
Subsea Tubular F6NM Martensitic SS
M - Martensitic Stainless SteelP - Fabrication WeldAp - OffshoreCd - Welding
Cm - Kalling Etched MacroDf - Welded Joint
Macrography of the longitudinal section of the broken link, at the fracture surface. There are several secondary cracks, parallel and perpendicular to the link axis.
38
VIEW
ML00079 / Jul.2017
Hydrogen Cracking of a Maritime Chain Link
M - High Strength Low AlloyP - Chain LinkAp - OffshoreCd - Hydrogen Embrittlement
Cm - Longitudinal Section AspectDf - Longitudinal Section

More from these cases

ML00074 — Hydrogen Cracking of a 17-4 PH Subsea BoltM - Precipitation Hardened Stainless SteelP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Macrography of a longitudinal section of the broken bolt, at the fracture position, showing that the fracture is partially flat (left side), where the macroscopically aspect is brittle, and a final ductile fracture (right side). Interesting to note that there is a large longitudinal crack, secondary (transverse to the fracture surface).
143
VIEW
ML00074 / Jun.2018
Hydrogen Cracking of a 17-4 PH Subsea Bolt
M - Precipitation Hardened Stainless SteelP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched MacroDf - Longitudinal Section
Detail of the brittle part of the bolt fracture, presenting a secondary cracking longitudinal to the bolt axis. The region of the bolt at the bottom of the thread (close to the surface) is brighter than the internal part of the bolt suggesting different fracture mechanisms.
111
VIEW
ML00074 / Jun.2018
Hydrogen Cracking of a 17-4 PH Subsea Bolt
M - Precipitation Hardened Stainless SteelP - FastenerAp - SubseaCd - Hydrogen Embrittlement
Cm - Fracture Surface AspectDf - Fracture
ML00072 — Liquation Cracks in a High Strength JointM - Low Alloy Medium Carbon QTP - Longitudinal Seam Welded PipeAp - O&G Well DrillingCd - Welding Defect
Hot cracking at the fusion line of the connector side, in a welded joint between a forging and a pipe, in a macrographic sample. The region of the heat affected zone of the connector presents a dendritic aspect suggesting that the forging reduction rate of the connector was not too high and did not broke the cast structure.
110
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 MacroDf - Welded Joint
ML00055 — CA6NM Blade Remanufactured by WeldingM - Martensitic Stainless SteelP - Remanufacture by WeldingAp - EnergyCd - Removed From Service
Macrography of a transverse section of the welded joint between the original casting and the inserted casting, in the side of the original part.
23
VIEW
ML00055 / Apr.2017
CA6NM Blade Remanufactured by Welding
M - Martensitic Stainless SteelP - Remanufacture by WeldingAp - EnergyCd - Removed From Service
Cm - Kalling Etched MacroDf - Fusion Line Left Side
Macrography of a transverse section of the welded joint between the original casting and the inserted casting, in the side of the inserted part.
17
VIEW
ML00055 / Apr.2017
CA6NM Blade Remanufactured by Welding
M - Martensitic Stainless SteelP - Remanufacture by WeldingAp - EnergyCd - Removed From Service
Cm - Kalling Etched MacroDf - Fusion Line Right Side
ML00053 — SAW Longitudinal Seam of X70 PipeM - Microalloyed SteelP - Longitudinal Seam Welded PipeAp - SubseaCd - Welding
Micrography of the fusion line of the second pass (not reheated). The HAZ is bainitic and the weld metal presents columnar grains (of the previous austenite).
61
VIEW
ML00053 / Mar.2017
SAW Longitudinal Seam of X70 Pipe
M - Microalloyed SteelP - Longitudinal Seam Welded PipeAp - SubseaCd - Welding
Cm - NItal Etched MacroDf - Fusion Line
ML00069 — Liquation Cracks in SAW of Low Carbon SteelM - Low Carbon SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
The macrography presents the position of the fracture in the superior plate (8 mm thickness).
61
VIEW
ML00069 / May.2017
Liquation Cracks in SAW of Low Carbon Steel
M - Low Carbon SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - NItal Etched MacroDf - Fracture
The macrography presents the position of the fracture in the fillet weld side.
67
VIEW
ML00069 / May.2017
Liquation Cracks in SAW of Low Carbon Steel
M - Low Carbon SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - NItal Etched MacroDf - Fracture
ML00045 — Subsea Tubular F6NM Martensitic SSM - Martensitic Stainless SteelP - Fabrication WeldAp - OffshoreCd - Welding
Macrography of the welded joint, at the root position, presenting the different zones studied in this ML. Transverse section. See the schematic drawing in the next image.
47
VIEW
ML00045 / Aug.2017
Subsea Tubular F6NM Martensitic SS
M - Martensitic Stainless SteelP - Fabrication WeldAp - OffshoreCd - Welding
Cm - Kalling Etched MacroDf - Welded Joint