Optical Microscope

7 cases · 54 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Microstructure: Secondary carbides clear all

Optical Microscope — sub-branches

As polished micrography 11Glyceregia Etched Micrography by OM 6Kalling Etched Micrography by OM 11Micrography by OM 8NaOH Electrolytic Etched Micro 5Nital Etched Micrography by OM 2Oxalic Acid Electrolytic Etch 11

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Aged microstructure of the HP stainless steel, modified with 1%Nb, cast fitting, tubular, operating for 6 years in a furnace which design temperature is 1100°C. The material presented a network of primary carbides, white and grey, and an austenitic matrix with coalescing secondary precipitation. Some voids. The Vickers identation indicates a hardness value about 260HV 100g in the aged austenitic matrix.
491
VIEW
ML00173 / May.2021
Welding Cracks in an Aged HP Cast Fitting
M - Heat Resistant SteelP - Cast FtittingAp - PetrochemicalCd - Welding
Cm - Kalling Etched Micrography by OMDf - Microhardness identations
SAMPLE 1 AT THE FRACTURE - Micrography in low magnification where the thickness is reduced to zero (fracture). Side A (process side) to the bottom and side B (furnace environment side) to the top.
85
VIEW
ML00160 / Apr.2020
High Temperature Degradation of 310SS
M - Austenitic Stainless SteelP - Rectangular TubeAp - Chemical IndustryCd - Scaling
Cm - Oxalic Acid Electrolytic EtchDf - Low Mag
Micrography of the tool steel, in the longitudinal section of the part. The material presented a uniform structure, tempered martensite. The tempering was in low temperature since the hardness is high (58 HRc at the surface).
87
VIEW
ML00084 / Mar.2020
Walrus Tool Steel
M - High Carbon Tool SteelP - ForgingAp - Mechanical IndustryCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Uniform Structure
Micrography of the new tube close to a region of a casting defect (shrinkage), presenting only austenitic structure with a network of primary precipitates.
351
VIEW
ML00097 / Nov.2017
Cast SS Tube Removed From High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - High Temperature
Cm - Glyceregia Etched Micrography by OMDf - Austenitic with Primary Carbides
Micrographic aspect of the corrosion damage in a section transverse to the pitting.
167
VIEW
ML00054 / Dec.2018
Cutlery Corrosion
M - Martensitic Stainless SteelP - Foodstuff ArticleAp - KitchenCd - Pitting Corrosion
Cm - Kalling Etched Micrography by OMDf - Pitting
Micrography of the transverse section of the NEW TUBE, in the center of the thickness, showing the austenitic structure with primary carbides network.
410
VIEW
ML00038 / Apr.2017
Cast SS Tube for High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - Creep
Cm - Glyceregia Etched Micrography by OMDf - Austenitic with Primary Carbides
The intake valve seat cylinder, manufactured in a high alloy white cast iron, presents a network of primary carbides, not degradated even after high temperature exposition during all lifetime.
632
VIEW
ML00003 / Apr.2017
Cast iron Engine Valve Seats
M - White Cast IronP - Valve SeatAp - MaritimeCd - Microstructural Evolution
Cm - Micrography by OMDf - Network of Primary Carbides

More from these cases

ML00173 — Welding Cracks in an Aged HP Cast FittingM - Heat Resistant SteelP - Cast FtittingAp - PetrochemicalCd - Welding
Cast fitting microstructure. Network of primary carbides and austenitic matrix with coalescing secondary precipitation.
37
VIEW
ML00173 / May.2021
Welding Cracks in an Aged HP Cast Fitting
M - Heat Resistant SteelP - Cast FtittingAp - PetrochemicalCd - Welding
Cm - Kalling Etched Micrography by OMDf - Base Metal
Cast fitting microstructure. The material presented a network of primary carbided and an austenitic matrix with coalescing secondary precipitation.
37
VIEW
ML00173 / May.2021
Welding Cracks in an Aged HP Cast Fitting
M - Heat Resistant SteelP - Cast FtittingAp - PetrochemicalCd - Welding
Cm - Kalling Etched Micrography by OMDf - Aged Microstructure
Micrographic detail of the network of primary carbided, white and grey, and an austenitic matrix with coalescing secondary precipitation.
30
VIEW
ML00173 / May.2021
Welding Cracks in an Aged HP Cast Fitting
M - Heat Resistant SteelP - Cast FtittingAp - PetrochemicalCd - Welding
Cm - Kalling Etched Micrography by OMDf - Aged Microstructure
Fusion line between the aged base metal (in the top) and the weld metal (in the bottom). The adopted filler metal is similar to the base metal.
27
VIEW
ML00173 / May.2021
Welding Cracks in an Aged HP Cast Fitting
M - Heat Resistant SteelP - Cast FtittingAp - PetrochemicalCd - Welding
Cm - Kalling Etched Micrography by OMDf - Fusion Line
Fusion line between the aged base metal (in the top) and the weld metal (in the bottom). There is a region where the primary carbides melted (partially melted zone), that appears dark, and a region of high dilution cloe to the fusion line.
26
VIEW
ML00173 / May.2021
Welding Cracks in an Aged HP Cast Fitting
M - Heat Resistant SteelP - Cast FtittingAp - PetrochemicalCd - Welding
Cm - Kalling Etched Micrography by OMDf - Fusion Line

+5 more from this case →

ML00160 — High Temperature Degradation of 310SSM - Austenitic Stainless SteelP - Rectangular TubeAp - Chemical IndustryCd - Scaling
SAMPLE 1 AT THE FRACTURE - Micrography at the position where the thickness is reduced to zero. Side A to the bottom. The microstructure is austenite with intergranular and transgranular precipitation. The position of the zero thickness presents aspect of an intergranular fracture, and in side A there are several intergranular cracks from the surface.
83
VIEW
ML00160 / Apr.2020
High Temperature Degradation of 310SS
M - Austenitic Stainless SteelP - Rectangular TubeAp - Chemical IndustryCd - Scaling
Cm - Oxalic Acid Electrolytic EtchDf - Austenitic with Secondary Precipitation
SAMPLE 1 AT THE FRACTURE - Micrographic detail of the intergranular fracture. The austenitic grains of the material are loosing.
80
VIEW
ML00160 / Apr.2020
High Temperature Degradation of 310SS
M - Austenitic Stainless SteelP - Rectangular TubeAp - Chemical IndustryCd - Scaling
Cm - Oxalic Acid Electrolytic EtchDf - Intergranular Fracture
SAMPLE 1 AT 1 mm THICKNESS - Micrography in low magnification in the center of the thickness. The microstructure is austenitic with secondary intergranular and intragranular precipitation.
76
VIEW
ML00160 / Apr.2020
High Temperature Degradation of 310SS
M - Austenitic Stainless SteelP - Rectangular TubeAp - Chemical IndustryCd - Scaling
Cm - Oxalic Acid Electrolytic EtchDf - Low Mag
SAMPLE 1 AT 1 mm THICKNESS - Micrography in the center of the thickness. The microstructure is austenitic with secondary precipitation, intergranular and intragranular.
76
VIEW
ML00160 / Apr.2020
High Temperature Degradation of 310SS
M - Austenitic Stainless SteelP - Rectangular TubeAp - Chemical IndustryCd - Scaling
Cm - Oxalic Acid Electrolytic EtchDf - Austenitic with Secondary Precipitation
SAMPLE 1 AT 1 mm THICKNESS - Micrographic detail of the austenite with secondary precipitation. This oxalic acid electrolytic etch is revealing the integranular and transgranular (or intragranular) precipitation. In the grain boundaries it is possible to see: 1) a continuous network of carbide precipitation and 2) isolated islands of sigma phase. In the middle of the grains there are rounded and neddles like carbides.
72
VIEW
ML00160 / Apr.2020
High Temperature Degradation of 310SS
M - Austenitic Stainless SteelP - Rectangular TubeAp - Chemical IndustryCd - Scaling
Cm - Oxalic Acid Electrolytic EtchDf - Austenitic with Secondary Precipitation

+16 more from this case →

ML00084 — Walrus Tool SteelM - High Carbon Tool SteelP - ForgingAp - Mechanical IndustryCd - Removed From Service
Micrographic detail of the tool steel, in the longitudinal section of the part. The material presented a uniform structure, tempered martensite, with small secondary carbides. The hardness in the section is 59 HRc.
73
VIEW
ML00084 / Mar.2020
Walrus Tool Steel
M - High Carbon Tool SteelP - ForgingAp - Mechanical IndustryCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Martensite
ML00097 — Cast SS Tube Removed From High Temperature ServiceM - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - High Temperature
Micrography close to the external surface of a new tube, sound.
48
VIEW
ML00097 / Nov.2017
Cast SS Tube Removed From High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - High Temperature
Cm - As polished micrographyDf - Close to the External Surface
Micrography close to the internal surface of a new tube, presenting casting defects.
47
VIEW
ML00097 / Nov.2017
Cast SS Tube Removed From High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - High Temperature
Cm - As polished micrographyDf - Close to the Internal Surface
Micrography of the tube removed from service after 6 month, close to a region of a casting defect (shrinkage), presenting austenitic structure with a network of primary precipitates (initial stage of coarsening) and intragranular secondary precipitation.
48
VIEW
ML00097 / Nov.2017
Cast SS Tube Removed From High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - High Temperature
Cm - Glyceregia Etched Micrography by OMDf - Intragranular Secondary Precipitation
Micrography close to the internal surface of the tube removed from service after 6 month, presenting high temperature oxidation and shrinkage voids (casting defects).
31
VIEW
ML00097 / Nov.2017
Cast SS Tube Removed From High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - High Temperature
Cm - As polished micrographyDf - Close to the Internal Surface
Micrography close to the external surface of the tube removed from service, damaged by high temperature oxidation.
25
VIEW
ML00097 / Nov.2017
Cast SS Tube Removed From High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - High Temperature
Cm - As polished micrographyDf - Close to the External Surface
ML00038 — Cast SS Tube for High Temperature ServiceM - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - Creep
Micrography of the transverse section of the NEW TUBE, close to the external surface, showing the austenitic structure with primary carbides network.
59
VIEW
ML00038 / Apr.2017
Cast SS Tube for High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - Creep
Cm - Glyceregia Etched Micrography by OMDf - Close to the External Surface
The micrography in the as polished condition of the NEW TUBE shows that there are no casting defects close to the external surface.
49
VIEW
ML00038 / Apr.2017
Cast SS Tube for High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - Creep
Cm - Micrography by OMDf - Close to the External Surface
The micrography in the as polished condition of the NEW TUBE shows that there are no casting defects in the center of the thickness.
47
VIEW
ML00038 / Apr.2017
Cast SS Tube for High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - Creep
Cm - Micrography by OMDf - Transverse Section
Micrography of the transverse section of the TUBE REMOVED FROM SERVICE, in the center of the thickness, showing the austenitic structure with primary carbides network and secondary precipitation.
59
VIEW
ML00038 / Apr.2017
Cast SS Tube for High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - Creep
Cm - Glyceregia Etched Micrography by OMDf - Intragranular Secondary Precipitation
Micrography of the transverse section of the TUBE REMOVED FROM SERVICE,close to the external surface, showing the austenitic structure with coalesced carbides and secondary precipitation.
39
VIEW
ML00038 / Apr.2017
Cast SS Tube for High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - Creep
Cm - Glyceregia Etched Micrography by OMDf - Close to the External Surface

+2 more from this case →

ML00003 — Cast iron Engine Valve SeatsM - White Cast IronP - Valve SeatAp - MaritimeCd - Microstructural Evolution
The intake valve seat cylinder, manufactured in a high alloy white cast iron, presents a network of primary carbides, not degradated even after high temperature exposition during all lifetime.
206
VIEW
ML00003 / Apr.2017
Cast iron Engine Valve Seats
M - White Cast IronP - Valve SeatAp - MaritimeCd - Microstructural Evolution
Cm - Micrography by OMDf - Network of Primary Carbides
The exhaust valve seat cylinder, manufactured in a high alloy white cast iron, presents a coalesced structure, degradated by high temperature exposition during the lifetime.
182
VIEW
ML00003 / Apr.2017
Cast iron Engine Valve Seats
M - White Cast IronP - Valve SeatAp - MaritimeCd - Microstructural Evolution
Cm - Micrography by OMDf - Coalesced structure
The exhaust valve seat cylinder, manufactured in a high alloy white cast iron, presents a coalesced structure, degradated by high temperature exposition during the lifetime.
137
VIEW
ML00003 / Apr.2017
Cast iron Engine Valve Seats
M - White Cast IronP - Valve SeatAp - MaritimeCd - Microstructural Evolution
Cm - Micrography by OMDf - Coalesced structure