Intergranular Cracking

13 cases · 30 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Standard: UNS Capture method: Optical Microscope clear all

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Micrographic aspect of the multiple intergranular cracks, initiating from the bottom of a pit.
25
VIEW
ML00172 / Mar.2021
Brittle Fracture of a LAS Valve Spring
M - Low Alloy Medium Carbon QTP - SpringAp - Oil and GasCd - Brittle Fracture
Cm - As polished micrographyDf - Intergranular Cracking
Micrography close to the external surface (to the top). The layer of intergranular corrosion shows evidences of selective leaching (suggesting that the aluminum was preferentially consumed). The stress corrosion cracking starts from the intergranularly corroded layer.
113
VIEW
ML00165 / Jul.2020
SCC of Aluminum Bronze Heating Coil
M - Aluminum BronzeP - Seamless tubeAp - Oil and GasCd - Stress Corrosion
Cm - FeCl3+HCl+H2O Etched MicroDf - Intergranular Cracking
Micrography of a longitudinal section of the bolt, in a position close to the fracture (top) and bolt surface (left ), presenting several secondary intergranular cracks.
57
VIEW
ML00139 / Jun.2018
Hydrogen Fracture of a 17-4 PH Allen Bolt
M - Precipitation Hardened Stainless SteelP - Allen BoltAp - SubseaCd - Hydrogen Embrittlement
Cm - As polished micrographyDf - Intergranular Cracking
Micrography of a longitudinal section of the spring indicating that under the deposits there are intergranular cracks initiating at the spring surface.
72
VIEW
ML00137 / Mar.2021
Brittle Fracture of a 15-5 PH Valve Spring
M - Precipitation Hardened Stainless SteelP - SpringAp - Oil and GasCd - Brittle Behavior
Cm - As polished micrographyDf - Intergranular Cracking
Micrography of the longitudinal section of the stud at the fracture (top of the figure) of a brittle intergranular aspect.
24
VIEW
ML00127 / May.2018
Hydrogen Cracks of Cadmium Plated Studs
M - Low Alloy Medium Carbon QTP - Allen StudAp - Oil and GasCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Intergranular Cracking
Micrographic detail of a transverse section of the ring, showing the corroded martensitic structure (chemical dissolution) inside the pitting.
33
VIEW
ML00124 / Feb.2018
MIC of a Martensitic Valve Ring
M - Martensitic Stainless SteelP - ForgingAp - EnergyCd - Brittle Behavior
Cm - As polished micrographyDf - Intergranular Cracking
Micrographic detail of the longitudinal section of the link, presenting internal cracks of intergranular morphology, typical of a hydrogen assisted mechanism.
52
VIEW
ML00079 / Jul.2017
Hydrogen Cracking of a Maritime Chain Link
M - High Strength Low AlloyP - Chain LinkAp - OffshoreCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Intergranular Cracking
Micrographic detail of a longitudinal section of the connector, at the fracture surface (in the top), showing intergranular secondary cracks.
54
VIEW
ML00078 / Jun.2017
Hydrogen Cracking of IN 718 Subsea Connector
M - NiCrFe AlloyP - ForgingAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Intergranular Cracking

More from these cases

ML00172 — Brittle Fracture of a LAS Valve SpringM - Low Alloy Medium Carbon QTP - SpringAp - Oil and GasCd - Brittle Fracture
Micrographic detail of the intergranular cracks, initiating from the bottom of a pit.
29
VIEW
ML00172 / Mar.2021
Brittle Fracture of a LAS Valve Spring
M - Low Alloy Medium Carbon QTP - SpringAp - Oil and GasCd - Brittle Fracture
Cm - As polished micrographyDf - Intergranular Cracking
ML00139 — Hydrogen Fracture of a 17-4 PH Allen BoltM - Precipitation Hardened Stainless SteelP - Allen BoltAp - SubseaCd - Hydrogen Embrittlement
Micrographic detail of the secondary intergranular cracks close to the surface of the bolt, where the fracture occurred.
56
VIEW
ML00139 / Jun.2018
Hydrogen Fracture of a 17-4 PH Allen Bolt
M - Precipitation Hardened Stainless SteelP - Allen BoltAp - SubseaCd - Hydrogen Embrittlement
Cm - As polished micrographyDf - Intergranular Cracking
Micrographic detail of the intergranular cracks in the transition between the threaded body and the head of the non broken bolt, indicating that this bolt was also embrittled and could fail soon.
48
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 Micrography by OMDf - Intergranular Cracking
ML00137 — Brittle Fracture of a 15-5 PH Valve SpringM - Precipitation Hardened Stainless SteelP - SpringAp - Oil and GasCd - Brittle Behavior
Micrographic detail of a longitudinal section of the spring indicating that under the deposits there are intergranular cracks initiating at the spring surface.
65
VIEW
ML00137 / Mar.2021
Brittle Fracture of a 15-5 PH Valve Spring
M - Precipitation Hardened Stainless SteelP - SpringAp - Oil and GasCd - Brittle Behavior
Cm - As polished micrographyDf - Intergranular Cracking
Micrographic detail of a longitudinal section of the spring indicating that under the deposits there are intergranular cracks initiating at the spring surface.
60
VIEW
ML00137 / Mar.2021
Brittle Fracture of a 15-5 PH Valve Spring
M - Precipitation Hardened Stainless SteelP - SpringAp - Oil and GasCd - Brittle Behavior
Cm - Kalling Etched Micrography by OMDf - Intergranular Cracking
Micrography of a longitudinal section of the spring indicating that under the deposits there are intergranular cracks initiating at the spring surface.
57
VIEW
ML00137 / Mar.2021
Brittle Fracture of a 15-5 PH Valve Spring
M - Precipitation Hardened Stainless SteelP - SpringAp - Oil and GasCd - Brittle Behavior
Cm - Kalling Etched Micrography by OMDf - Intergranular Cracking
Micrographic detail of a longitudinal section of the spring indicating that under the deposits there are intergranular cracks initiating at the spring surface.
57
VIEW
ML00137 / Mar.2021
Brittle Fracture of a 15-5 PH Valve Spring
M - Precipitation Hardened Stainless SteelP - SpringAp - Oil and GasCd - Brittle Behavior
Cm - Kalling Etched Micrography by OMDf - Intergranular Cracking
ML00124 — MIC of a Martensitic Valve RingM - Martensitic Stainless SteelP - ForgingAp - EnergyCd - Brittle Behavior
Micrographic detail of a transverse section of the ring at the cracking position. The cracks are intergranular and opened at the position close to the surface. it is possible to identify dissolution of the structure adjacent to the grain boundaries,
24
VIEW
ML00124 / Feb.2018
MIC of a Martensitic Valve Ring
M - Martensitic Stainless SteelP - ForgingAp - EnergyCd - Brittle Behavior
Cm - Kalling Etched Micrography by OMDf - Intergranular Cracking
Micrography of a transverse section, in the center of the ring, where the cracking was closed. The cracks are thin, not corroded, intergranular and not connected to the surface, indicating a hydrogen embrittlement effect.
25
VIEW
ML00124 / Feb.2018
MIC of a Martensitic Valve Ring
M - Martensitic Stainless SteelP - ForgingAp - EnergyCd - Brittle Behavior
Cm - Kalling Etched Micrography by OMDf - Intergranular Cracking
ML00079 — Hydrogen Cracking of a Maritime Chain LinkM - High Strength Low AlloyP - Chain LinkAp - OffshoreCd - Hydrogen Embrittlement
Micrographic detail of the longitudinal section of the link, close to the fracture surface, presenting the intergranular morphology of the secondary cracks, parallel to the fracture.
29
VIEW
ML00079 / Jul.2017
Hydrogen Cracking of a Maritime Chain Link
M - High Strength Low AlloyP - Chain LinkAp - OffshoreCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Intergranular Cracking
Micrographic detail of the intergranular secondary cracks, parallel to the fracture, typical of a hydrogen assisted cracking.
29
VIEW
ML00079 / Jul.2017
Hydrogen Cracking of a Maritime Chain Link
M - High Strength Low AlloyP - Chain LinkAp - OffshoreCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Intergranular Cracking