Optical Microscope

5 cases · 10 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Standard: ASTM Detail focus: Intergranular Cracking clear all

Optical Microscope — sub-branches

As polished micrography 2Kalling Etched Micrography by OM 1Micrography by OM 2Micrography by OM using A262 Method A 3Nital Etched Micrography by OM 2

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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
Micrographic detail of the intergranular cracks.
42
VIEW
ML00138 / Jun.2018
Liquid Metal Embrittlement of a HSLA Steel
M - High Strength Low AlloyP - Coated ProductAp - Mechanical IndustryCd - Liquid Metal Embrittlement
Cm - Nital Etched Micrography by OMDf - Intergranular Cracking
The micrographic aspect of the cracks in a section transverse to the weld (the removed sample), shows that there are cracks with different sizes, the larger are filled with products that indicate they were opened for longer times.
67
VIEW
ML00071 / Jan.2019
Reheating Cracking of a CrMo Vessel Weld
M - CrMo SteelP - In Field WeldAp - EnergyCd - Welding Defect
Cm - Nital 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

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
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