Optical Microscope

6 cases · 23 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Microstructure: Secondary carbides Detail focus: Microstructure clear all

Optical Microscope — sub-branches

Glyceregia Etched Micrography by OM 4Kalling Etched Micrography by OM 3Micrography by OM 4NaOH Electrolytic Etched Micro 3Nital Etched Micrography by OM 2Oxalic Acid Electrolytic Etch 7

Results

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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
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
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
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
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
Same region as the previous figure, showing the structure of the base metal and weld metal, at the cracked area. In the base metal, the cracks are associated to the primary carbides network and in the weld metal it is associated to the solidification columnar grains.
110
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
ML00160 — High Temperature Degradation of 310SSM - Austenitic Stainless SteelP - Rectangular TubeAp - Chemical IndustryCd - Scaling
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
SAMPLE 2 AT 2 mm THICKNESS - Micrography in the center of the thickness. The microstructure is austenitic with secondary precipitation, intergranular and intragranular. There are no variations in the microstructure comparing to sample 1.
48
VIEW
ML00160 / Apr.2020
High Temperature Degradation of 310SS
M - Austenitic Stainless SteelP - Rectangular TubeAp - Chemical IndustryCd - Scaling
Cm - Oxalic Acid Electrolytic EtchDf - Secondary Precipitation
SAMPLE 2 AT 2 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. There are no variations in the microstructure comparing to sample 1.
43
VIEW
ML00160 / Apr.2020
High Temperature Degradation of 310SS
M - Austenitic Stainless SteelP - Rectangular TubeAp - Chemical IndustryCd - Scaling
Cm - Oxalic Acid Electrolytic EtchDf - Intergranular Precipitation
SAMPLE 3 AT 4 mm THICKNESS - Micrography in the center of the thickness. The microstructure is austenitic with secondary intergranular and intragranular precipitation, but this micrography was obtained in the longitudinal section, presenting the plate alignment and was etched with NaOH, adopted to colour the sigma phase.
45
VIEW
ML00160 / Apr.2020
High Temperature Degradation of 310SS
M - Austenitic Stainless SteelP - Rectangular TubeAp - Chemical IndustryCd - Scaling
Cm - NaOH Electrolytic Etched MicroDf - Austenitic with Secondary Precipitation

+4 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 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
ML00038 — Cast SS Tube for High Temperature ServiceM - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - Creep
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
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