UNS

12 cases · 21 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Capture method: Kalling Etched Macro clear all

UNS — sub-branches

A03560 2A08500 1A96061 1C12000 1C28000 1C36000 1C60800 1C68700 1C70600 1C85710 1C92200 1C95300 1F11701 1F32800 2F34800 1G10050 1G10080 1G10100 1G10200 2G10450 2G10500 1G10550 1G10600 1G10700 2G10800 2G10900 1G12110 1G15220 mod 1G15240 1G41300 4G41400 3G43400 1G48200 1G61500 1G86300 2J23055 1J91540 2J92900 1K03101 2K81340 1N02200 1N04400 1N07718 7N08705 1R50400 2R56400 3S15500 1S17400 3S17700 1S21800 2S30300 1S30400 4S30403 1S30409 1S31600 4S31603 3S32304 1S32750 5S32760 2S40900 2S41500 1S42000 3S43100 mod 1T31501 1

Results

SortNewestOldestTitle A-ZTitle Z-A
This macrography shows a longitudinal section of the tubular cast fitting. The external side is to the top and the internal side to the bottom. The buttering layer is evident in the groove that would be welded to the centrifugall cast tube (right side) and part of the ID and OD. During the buttering welding of the casting the cracks were not detected because they were formed in the center of the thickness and some have propagated to the internal diameter, but not to the external diameter. They opened only when the buttered casting was welded to the tube.
20
VIEW
ML00173 / May.2021
Welding Cracks in an Aged HP Cast Fitting
M - Heat Resistant SteelP - Cast FtittingAp - PetrochemicalCd - Welding
Cm - Kalling Etched MacroDf - Longitudinal Section
Macrography of the longidutinal section of a non broken allen bolt, at the threaded body to bolt head transition. The granular structure is different through the bolt, with refined structure in the threaded body and coarse at the transition.
44
VIEW
ML00139 / Jun.2018
Hydrogen Fracture of a 17-4 PH Allen Bolt
M - Precipitation Hardened Stainless SteelP - Allen BoltAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched MacroDf - Longitudinal Section
17-4 PH rod, tubular, OD 10.6mm, wall thickness about 3.5 mm. Macrography of the rod in a transverse section showing the pitting in a position where it is almost through wall.
86
VIEW
ML00121 / Feb.2018
Pitting Corrosion in a Subsea System
M - Austenitic / MartensiticP - Rod & CylinderAp - SubseaCd - Pitting Corrosion
Cm - Kalling Etched MacroDf - Pitting
Macrography of a longitudinal section of the fitting to tubing weld, with the longitudinal cracking at the tubular fitting position.
69
VIEW
ML00094 / Sep.2017
MIC of a Subsea Hydraulic Line
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Behavior
Cm - Kalling Etched MacroDf - Longitudinal Section
The macrography shows the longitudinal section of the allen bolt, 1/2" nominal diameter, that was machined from a heat treated bar (solution annealed and aged). The granular structure presents differences in the grain sizes. At the bolt head (external surface of the original bar) the austenitic grain size is larger than in the center of the bar where the particles in segregated bands "arrested" the grains during hot forming and solution annealing.
58
VIEW
ML00089 / Sep.2017
Inconel 718 Allen Bolt for Subsea Application
M - NiCrFe AlloyP - Machined PartAp - SubseaCd - Typical manufacturing
Cm - Kalling Etched MacroDf - Machined Thread
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
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
Micrographic detail of a longitudinal section of the connector, at the fracture surface (in the top), showing intergranular secondary cracks. There is a large amount of delta phase precipitated intergranular and intragranluar.
49
VIEW
ML00078 / Jun.2017
Hydrogen Cracking of IN 718 Subsea Connector
M - NiCrFe AlloyP - ForgingAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched MacroDf - Intergranular Cracking

More from these cases

ML00173 — Welding Cracks in an Aged HP Cast FittingM - Heat Resistant SteelP - Cast FtittingAp - PetrochemicalCd - Welding
Macrographic detail close to the internal diameter (ID in the bottom), where the cracks were detected by dye check (after removal of the damaged part of the cast fitting). Close to the surface it is possible to see the layers of the weld metal that corresponds to the cast fitting buttering.
21
VIEW
ML00173 / May.2021
Welding Cracks in an Aged HP Cast Fitting
M - Heat Resistant SteelP - Cast FtittingAp - PetrochemicalCd - Welding
Cm - Kalling Etched MacroDf - Cracks
Welding Cracks in an Aged HP Cast Fitting
2
VIEW
ML00173 / May.2021
Welding Cracks in an Aged HP Cast Fitting
M - Heat Resistant SteelP - Cast FtittingAp - PetrochemicalCd - Welding
Cm - Kalling Etched MacroDf - Cracks
Welding Cracks in an Aged HP Cast Fitting
1
VIEW
ML00173 / May.2021
Welding Cracks in an Aged HP Cast Fitting
M - Heat Resistant SteelP - Cast FtittingAp - PetrochemicalCd - Welding
Cm - Kalling Etched MacroDf - Microhardness identations
ML00094 — MIC of a Subsea Hydraulic LineM - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Behavior
Macrography of the fitting to tubing welded joint. The internal surface of the fitting (left side) is rough compared to the internal surface of the tubing (right side). The cracking is located only in the fitting and presented no association with the welded joint.
41
VIEW
ML00094 / Sep.2017
MIC of a Subsea Hydraulic Line
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Behavior
Cm - Kalling Etched MacroDf - Longitudinal Section
ML00089 — Inconel 718 Allen Bolt for Subsea ApplicationM - NiCrFe AlloyP - Machined PartAp - SubseaCd - Typical manufacturing
Micrographic detail of a longitudinal section of the bolt, in the center of the thickness (ND 1/2"). Although the material was hardened by heat treatment (solution annealing and aging), the microstructure observed by optical microscopy does not reveal the intragranular precipitation.
33
VIEW
ML00089 / Sep.2017
Inconel 718 Allen Bolt for Subsea Application
M - NiCrFe AlloyP - Machined PartAp - SubseaCd - Typical manufacturing
Cm - Kalling Etched MacroDf - Austenite
The micrography of a longitudinal section, at the bolt head close to the surface of the original bar. In this region the material increased the grain size due to the lack of particles (inclusions), to "arrest" the grain boundaries (during hot forming and solution annealing). The smaller grain size is located in the center of the bar, that concentrated the inclusions.
30
VIEW
ML00089 / Sep.2017
Inconel 718 Allen Bolt for Subsea Application
M - NiCrFe AlloyP - Machined PartAp - SubseaCd - Typical manufacturing
Cm - Kalling Etched MacroDf - Dual grain sizes
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