Atlas

6 cases · 9 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Microstructure: Austenite Capture method: Optical Microscope Detail focus: Intergranular Cracking clear all

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Detailed microstructure of the heat affected zone, fully carburized and cracked intergranular. Large austenitic grain size.
19
VIEW
ML00174 / Jul.2021
Carburization of a 347 SS Welded Joint
M - Austenitic Stainless SteelP - Fabrication WeldAp - EnergyCd - Carburization
Cm - Oxalic Acid Electrolytic EtchDf - Intergranular Cracking
SAMPLE 1, AT THE FRACTURE - Micrographic detail, as polished, of the oxides that are penetrating in the austenitic grain boundaries. The oxidation created intergranular cracks in regions close to the edge of the rectangular tube, that are more susceptible to suffer cyclic thermal stresses, since the furnace is weekly turned off, during two days.
55
VIEW
ML00160 / Apr.2020
High Temperature Degradation of 310SS
M - Austenitic Stainless SteelP - Rectangular TubeAp - Chemical IndustryCd - Scaling
Cm - As polished micrographyDf - 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
Micrographic detail of a longitudinal section of the stud, at the fracture surface, in the thread. It is possible to see primary precipitates (yellow) already cracked and intergranular propagation.
37
VIEW
ML00075 / Jun.2018
Hydrogen Cracking of IN 718 Subsea Fasteners
M - NiCrFe AlloyP - StudAp - SubseaCd - Hydrogen Embrittlement
Cm - Kalling Etched Micrography by OMDf - Intergranular Cracking
Micrography of a section transverse to the repair weld showing that the macroscopic crack, detected at the surface of the plate, occurred exactly at the margin of the weld bead. It is possible to see that the bead was deposited over a region that was already corroded (intergranular corrosion) and the macroscopic crack is the opening of several corroded grains.
158
VIEW
ML00015 / Oct.2017
Intergranular Corrosion of 304SS Plate
M - Austenitic Stainless SteelP - Rolled PlateAp - RefineryCd - Intergranular Corrosion
Cm - Micrography by OM using A262 Method ADf - Intergranular Cracking
Transverse section of the fitting that suffered a longitudinal cracking. As polished. The wrought fitting has suffered intergranular stress corrosion cracking from the internal surface, exposed to hot caustic environment.
566
VIEW
ML00011 / Oct.2017
Intergranular SCC of Pure Nickel
M - Unalloyed NickelP - Wrought FittingAp - Chemical IndustryCd - Stress Corrosion
Cm - Micrography by OMDf - Intergranular Cracking

More from these cases

ML00015 — Intergranular Corrosion of 304SS PlateM - Austenitic Stainless SteelP - Rolled PlateAp - RefineryCd - Intergranular Corrosion
Detail of the fusion line region of the repair weld. It is possible to see that the cracks are filled with oxides indicating that the material was already corroded when the bead was deposited.
128
VIEW
ML00015 / Oct.2017
Intergranular Corrosion of 304SS Plate
M - Austenitic Stainless SteelP - Rolled PlateAp - RefineryCd - Intergranular Corrosion
Cm - Micrography by OM using A262 Method ADf - Intergranular Cracking
Detail of the fusion line region of the repair weld. It is possible to see that the cracks are filled with oxides indicating that the material was already corroded when the bead was deposited.
108
VIEW
ML00015 / Oct.2017
Intergranular Corrosion of 304SS Plate
M - Austenitic Stainless SteelP - Rolled PlateAp - RefineryCd - Intergranular Corrosion
Cm - Micrography by OM using A262 Method ADf - Intergranular Cracking
ML00011 — Intergranular SCC of Pure NickelM - Unalloyed NickelP - Wrought FittingAp - Chemical IndustryCd - Stress Corrosion
Transverse section of the fitting that suffered a longitudinal cracking. As polished. The wrought fitting has suffered intergranular stress corrosion cracking from the internal surface, exposed to hot caustic environment.
70
VIEW
ML00011 / Oct.2017
Intergranular SCC of Pure Nickel
M - Unalloyed NickelP - Wrought FittingAp - Chemical IndustryCd - Stress Corrosion
Cm - Micrography by OMDf - Intergranular Cracking