Optical Microscope

10 cases · 57 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Microstructure: Bainite Detail focus: Microstructure clear all

Optical Microscope — sub-branches

As polished micrography 2Chromic Acid Electrolytic Etched 3Micrography by OM 2Nital Etched Micrography by OM 41Oxalic Acid Electrolytic Etch 9

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The micrography shows the martensitic region of the tube HAZ responsible for the hydrogen cracking, presenting too high hardness level (600 HV). It is a fresh martensite since the joint was welded in one pass and there was no PWHT.
45
VIEW
ML00052 / Apr.2017
Cold Cracks in API 5CT L80 Tube Welded to a Structural Part
M - Low Alloy SteelP - Seamless tubeAp - OffshoreCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Martensite
Micrography of a longitudinal section of the mooring chain in the base metal. The low magnification reveals the banded structure of the rolled bar. The base metal microstructure is bainitic..
79
VIEW
ML00013 / Apr.2017
Welding Cracks in Mooring Chain
M - Low Alloy Low Carbon QTP - Welded PartAp - OffshoreCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Banded Structure

More from these cases

ML00052 — Cold Cracks in API 5CT L80 Tube Welded to a Structural PartM - Low Alloy SteelP - Seamless tubeAp - OffshoreCd - Welding Defect
Micrography of the low alloy steel tube at the fusion line, presenting a martensitic structure at the HAZ and acicular ferrite in the weld metal.
41
VIEW
ML00052 / Apr.2017
Cold Cracks in API 5CT L80 Tube Welded to a Structural Part
M - Low Alloy SteelP - Seamless tubeAp - OffshoreCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Fusion Line
ML00013 — Welding Cracks in Mooring ChainM - Low Alloy Low Carbon QTP - Welded PartAp - OffshoreCd - Welding Defect
Micrographic detail of the bainitic microstructure of the base metal in the longitudinal section.
72
VIEW
ML00013 / Apr.2017
Welding Cracks in Mooring Chain
M - Low Alloy Low Carbon QTP - Welded PartAp - OffshoreCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Bainite
Micrography of a longitudinal section of the mooring chain at the flash welded region. The banded structure is deformed by the upset, close to the weld metal that is ferritic-bainitic.
61
VIEW
ML00013 / Apr.2017
Welding Cracks in Mooring Chain
M - Low Alloy Low Carbon QTP - Welded PartAp - OffshoreCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Bainitic Ferrite
Micrographic detail of the ferritic-bainitic weld metal, autogenous flash butt weld.
56
VIEW
ML00013 / Apr.2017
Welding Cracks in Mooring Chain
M - Low Alloy Low Carbon QTP - Welded PartAp - OffshoreCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Bainitic Ferrite
Micrographic detail of the microcracks associated to segregated regions in a network morphology, probably due to the flash welding temperature and upset.
50
VIEW
ML00013 / Apr.2017
Welding Cracks in Mooring Chain
M - Low Alloy Low Carbon QTP - Welded PartAp - OffshoreCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Non Metallic Inclusions