Optical Microscope

10 cases · 95 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Product: Casting Condition: Damage clear all

Optical Microscope — sub-branches

As polished micrography 10H2SO4+HNO3+H3PO4 Etched Micro 3Kalling Etched Micrography by OM 5Keller Etched Micrography by OM 5Micrography by OM 8Nital Etched Micrography by OM 64

Results

SortNewestOldestTitle A-ZTitle Z-A
The wheel microstructure changed a little depending the thickness. In the region of WHEEL 1 fracture and WHEEL 2 cracking, it presented an alpha matrix with a networklike precipitates interdendritic.
46
VIEW
ML00183 / Dec.2022
Ductile Behavior of an Aluminum Wheel
M - Aluminum Silicon MagnesiumP - CastingAp - AutomotiveCd - Ductile Behavior
Cm - Keller Etched Micrography by OMDf - Hypoeutetic
Micrographic aspect, as polished, of the cast cylinder section at the fracture position (top of the figure), close to the internal surface (left side). It is possible to see large graphite flakes.
98
VIEW
ML00141 / Jul.2018
Brittle Fracture of a Corroded Gray Cast Iron
M - Gray Cast ironP - CastingAp - EngineCd - Brittle Fracture
Cm - As polished micrographyDf - Close to the Internal Surface
Micrography of the high strenght steel, heat treated, of the casting device. The microstructure is bainitic martensitic.
109
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 - Bainitic Martensitic
Micrography of a transverse section of the lifting part, showing interdendritic voids close to the surface at the inner diameter of the padeye. The microstructure is tempered martensite.
450
VIEW
ML00098 / Nov.2017
Brittle Fracture of a Casting Lifting Device
M - Low Alloy Medium Carbon QTP - CastingAp - LiftingCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Casting defects
Close to the camshaft lobe surface, the chilled casting presents a white cast iron structure. Primary carbides and ledeburite with a hardness level about 50 HRc.
102
VIEW
ML00060 / Apr.2017
Brittle Fracture of a Chilled Cast Iron Camshaft
M - Chilled Cast IronP - ShaftAp - AutomotiveCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Close to the External Surface
Transverse section of the blade showing large grains of this poliycristaline cast material.
421
VIEW
ML00042 / Apr.2017
Gas Turbine Blade IN 939, Coated
M - NiCrCo AlloyP - CastAp - Gas TurbineCd - Intergranular Cracking
Cm - H2SO4+HNO3+H3PO4 Etched MicroDf - Coarse Structure
The cast iron microstructure is predominatly ferritic with graphite nodules.
169
VIEW
ML00040 / Apr.2017
Brittle Fracture of a Valve Stem
M - Nodular Cast IronP - Valve StemAp - ShipCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Graphite in Nodules
Micrographic detail of the defect (void in the right side of the figure), as polished. In the left side it is the surface of the water blade and there are some non metalic inclusions in this region.
54
VIEW
ML00017 / Apr.2017
Casting Defect in CA6NM
M - Martensitic Stainless SteelP - Machined PartAp - EnergyCd - Casting Defect
Cm - Micrography by OMDf - Void

More from these cases

ML00183 — Ductile Behavior of an Aluminum WheelM - Aluminum Silicon MagnesiumP - CastingAp - AutomotiveCd - Ductile Behavior
Detail of the alpha matrix with an eutectic networklike precipitates, interdendritic. Presence of acicular iron rich phases (dark gray).
51
VIEW
ML00183 / Dec.2022
Ductile Behavior of an Aluminum Wheel
M - Aluminum Silicon MagnesiumP - CastingAp - AutomotiveCd - Ductile Behavior
Cm - Keller Etched Micrography by OMDf - Networklike precipitates
Micrography transverse to the fracture surface of the WHEEL 1. The fracture is in the up right position of the photo and it can be observed a secondary cracking following the interdendritic precipitates.
33
VIEW
ML00183 / Dec.2022
Ductile Behavior of an Aluminum Wheel
M - Aluminum Silicon MagnesiumP - CastingAp - AutomotiveCd - Ductile Behavior
Cm - Keller Etched Micrography by OMDf - Radial Section
Micrographic detail of the secondary crack from the fracture surface of the WHEEL 1, following the interdendritic precipitates.
36
VIEW
ML00183 / Dec.2022
Ductile Behavior of an Aluminum Wheel
M - Aluminum Silicon MagnesiumP - CastingAp - AutomotiveCd - Ductile Behavior
Cm - Keller Etched Micrography by OMDf - Fracture
Dendritic branching structure of the aluminum matrix, with fine interdendritic features visible against a darker surrounding phase.
2
VIEW
ML00183 / Dec.2022
Ductile Behavior of an Aluminum Wheel
M - Aluminum Silicon MagnesiumP - CastingAp - AutomotiveCd - Ductile Behavior
Cm - Keller Etched Micrography by OMDf - Crack
ML00141 — Brittle Fracture of a Corroded Gray Cast IronM - Gray Cast ironP - CastingAp - EngineCd - Brittle Fracture
Micrographic aspect, as polished, of the cast cylinder section at the fracture position (top of the figure), in the center of the thickness. It is possible to see a mixture of large graphite flakes and rosette grouping flakes.
80
VIEW
ML00141 / Jul.2018
Brittle Fracture of a Corroded Gray Cast Iron
M - Gray Cast ironP - CastingAp - EngineCd - Brittle Fracture
Cm - As polished micrographyDf - In the Center of the Thickness
Micrographic aspect, as polished, of the cast cylinder section at the fracture position (top of the figure), close to the external surface (left side). It is possible to see smaller graphite flakes, interdendritic .
79
VIEW
ML00141 / Jul.2018
Brittle Fracture of a Corroded Gray Cast Iron
M - Gray Cast ironP - CastingAp - EngineCd - Brittle Fracture
Cm - As polished micrographyDf - Close to the External Surface
Micrography of the longitudinal section of the cylinder, at the internal diameter (left side of the figure), in contact with the treated cooling water, presenting large graphite flakes in a predominatly perlitic matrix.
50
VIEW
ML00141 / Jul.2018
Brittle Fracture of a Corroded Gray Cast Iron
M - Gray Cast ironP - CastingAp - EngineCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Close to the Internal Surface
Micrography of the longitudinal section of the cylinder, at the internal diameter, in contact with the treated cooling water, presenting large graphite flakes in a predominatly perlitic matrix. It is important to mention that the flakes are almost interconnecting themelves.
47
VIEW
ML00141 / Jul.2018
Brittle Fracture of a Corroded Gray Cast Iron
M - Gray Cast ironP - CastingAp - EngineCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Graphite in Flakes
Micrography of the longitudinal section of the cylinder, at the internal diameter, in contact with the treated cooling water, presenting large graphite flakes in a predominatly perlitic matrix. It is important to mention that the flakes are almost interconnecting themelves.
48
VIEW
ML00141 / Jul.2018
Brittle Fracture of a Corroded Gray Cast Iron
M - Gray Cast ironP - CastingAp - EngineCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Predominantly Pearlitic

+19 more from this case →

ML00138 — Liquid Metal Embrittlement of a HSLA SteelM - High Strength Low AlloyP - Coated ProductAp - Mechanical IndustryCd - Liquid Metal Embrittlement
Micrography of the high strenght steel, heat treated, of the casting device. The microstructure is bainitic martensitic.
92
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 - Bainitic Martensitic
Micrographic detail of the high strenght steel microstructure, bainitic martensitic.
85
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 - Bainitic Martensitic
Micrographic detail of the zinc layer at the surface.
88
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 - Zn Layer
Micrography of the section transverse to the fracture (top of the figure). The fracture is intergranular, there are several secondary cracks, and there are deposits of zinc over the fracture. The zinc makes difficult the etch with Nital to reveal the microstructure close to the fracture surface.
67
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 - Fracture
Micrographic detail of the section transverse to the fracture (top of the figure), suggesting the intergranular morphology (at the previous austenite grain boundaries) and the deposits of zinc over the fracture that create a condition of protection of the base metal during the metallographic etch, and the material is not fully etched.
60
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 - Zn Layer

+12 more from this case →

ML00098 — Brittle Fracture of a Casting Lifting DeviceM - Low Alloy Medium Carbon QTP - CastingAp - LiftingCd - Brittle Fracture
Micrography of the lifting padeye showing a dendritic path of a quenched and tempered martensitic microstructure. The segregated regions (white interdendritic regions) are more clearly identified in low magnification. Voids are located in these segregated regions.
21
VIEW
ML00098 / Nov.2017
Brittle Fracture of a Casting Lifting Device
M - Low Alloy Medium Carbon QTP - CastingAp - LiftingCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Martensite
Micrography of the lifting padeye showing a quenched and tempered martensitic microstructure. Voids are located in interdendritic segregated regions.
20
VIEW
ML00098 / Nov.2017
Brittle Fracture of a Casting Lifting Device
M - Low Alloy Medium Carbon QTP - CastingAp - LiftingCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Martensite
Micrography of the lifting padeye showing a quenched and tempered martensitic microstructure. Voids are located in interdendritic segregated regions. At this magnification the segregation is not clear.
16
VIEW
ML00098 / Nov.2017
Brittle Fracture of a Casting Lifting Device
M - Low Alloy Medium Carbon QTP - CastingAp - LiftingCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Martensite
Micrography of the lifting padeye showing a quenched and tempered martensitic microstructure. The hardness level of the material is about 39 HRc.
14
VIEW
ML00098 / Nov.2017
Brittle Fracture of a Casting Lifting Device
M - Low Alloy Medium Carbon QTP - CastingAp - LiftingCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Martensite
Micrography of the secondary crack, paralel to fracture, starting from the internal diameter of the padeye. The crack propagates in an interdendritic morphology, interconnecting casting defects.
13
VIEW
ML00098 / Nov.2017
Brittle Fracture of a Casting Lifting Device
M - Low Alloy Medium Carbon QTP - CastingAp - LiftingCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Secondary Cracks

+8 more from this case →

ML00060 — Brittle Fracture of a Chilled Cast Iron CamshaftM - Chilled Cast IronP - ShaftAp - AutomotiveCd - Brittle Fracture
Micrographic detail of the chilled structure. Primary carbides, ledeburite and perlite islands.
79
VIEW
ML00060 / Apr.2017
Brittle Fracture of a Chilled Cast Iron Camshaft
M - Chilled Cast IronP - ShaftAp - AutomotiveCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Close to the External Surface
In the center of the shaft thickness the structure is perlitic with graphite in flakes, but there are also islands of ledeburite.
62
VIEW
ML00060 / Apr.2017
Brittle Fracture of a Chilled Cast Iron Camshaft
M - Chilled Cast IronP - ShaftAp - AutomotiveCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - In the Center of the Thickness
Micrographic detail of the structure in the center of the shaft thickness. Perlitic matrix with graphite in flakes, and ledeburite islands.
53
VIEW
ML00060 / Apr.2017
Brittle Fracture of a Chilled Cast Iron Camshaft
M - Chilled Cast IronP - ShaftAp - AutomotiveCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - In the Center of the Thickness
In the intermediary position of the shaft thickness (T/4) the amount of perlite increases in the matrix and primary carbides decreases compared to the chilled surface.
54
VIEW
ML00060 / Apr.2017
Brittle Fracture of a Chilled Cast Iron Camshaft
M - Chilled Cast IronP - ShaftAp - AutomotiveCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - T/4 of the external surface
Micrographic detail of the intermediary position of the shaft thickness (T/4). The amount of perlite increases in the matrix and primary carbides decreases compared with the chilled surface.
55
VIEW
ML00060 / Apr.2017
Brittle Fracture of a Chilled Cast Iron Camshaft
M - Chilled Cast IronP - ShaftAp - AutomotiveCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - T/4 of the external surface

+2 more from this case →

ML00042 — Gas Turbine Blade IN 939, CoatedM - NiCrCo AlloyP - CastAp - Gas TurbineCd - Intergranular Cracking
Micrography close to the surface of the blade, showing the diffusion coating (aluminum base alloy) that is still sound. No strong oxidation or erosion was detected.
53
VIEW
ML00042 / Apr.2017
Gas Turbine Blade IN 939, Coated
M - NiCrCo AlloyP - CastAp - Gas TurbineCd - Intergranular Cracking
Cm - H2SO4+HNO3+H3PO4 Etched MicroDf - Coating
Micrography as polished of the region where there was a refrigeration hole, presenting a cracking.
35
VIEW
ML00042 / Apr.2017
Gas Turbine Blade IN 939, Coated
M - NiCrCo AlloyP - CastAp - Gas TurbineCd - Intergranular Cracking
Cm - Micrography by OMDf - Cracking
The cracking from the refrigeration hole presents an intergranular morphology, as shown in the micrography of a transverse section of the blade.
35
VIEW
ML00042 / Apr.2017
Gas Turbine Blade IN 939, Coated
M - NiCrCo AlloyP - CastAp - Gas TurbineCd - Intergranular Cracking
Cm - H2SO4+HNO3+H3PO4 Etched MicroDf - Intergranular Cracking
ML00040 — Brittle Fracture of a Valve StemM - Nodular Cast IronP - Valve StemAp - ShipCd - Brittle Fracture
The micrography of the stem at the fracture region shows a flat fracture with transgranular clevage at the ferritic structure.
137
VIEW
ML00040 / Apr.2017
Brittle Fracture of a Valve Stem
M - Nodular Cast IronP - Valve StemAp - ShipCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Fracture
Micrography presenting a detail of the fracture surface opening to the graphite nodules.
139
VIEW
ML00040 / Apr.2017
Brittle Fracture of a Valve Stem
M - Nodular Cast IronP - Valve StemAp - ShipCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Fracture
ML00017 — Casting Defect in CA6NMM - Martensitic Stainless SteelP - Machined PartAp - EnergyCd - Casting Defect
Micrographic detail non metalic inclusions in the region where there are casting defects. As polished.
48
VIEW
ML00017 / Apr.2017
Casting Defect in CA6NM
M - Martensitic Stainless SteelP - Machined PartAp - EnergyCd - Casting Defect
Cm - Micrography by OMDf - Non Metallic Inclusions
Blade microstructure. Tempered martensite, (probably) retained austenite and delta ferrite islands.
55
VIEW
ML00017 / Apr.2017
Casting Defect in CA6NM
M - Martensitic Stainless SteelP - Machined PartAp - EnergyCd - Casting Defect
Cm - Kalling Etched Micrography by OMDf - Delta Ferrite Islands
Blade microstructure. Previous austenite coarse grains.
46
VIEW
ML00017 / Apr.2017
Casting Defect in CA6NM
M - Martensitic Stainless SteelP - Machined PartAp - EnergyCd - Casting Defect
Cm - Kalling Etched Micrography by OMDf - Coarse Structure
Blade microstructure. Tempered martensite, (probably) retained austenite and delta ferrite islands.
47
VIEW
ML00017 / Apr.2017
Casting Defect in CA6NM
M - Martensitic Stainless SteelP - Machined PartAp - EnergyCd - Casting Defect
Cm - Kalling Etched Micrography by OMDf - Delta Ferrite Islands
Region of a casting void in the blade.
33
VIEW
ML00017 / Apr.2017
Casting Defect in CA6NM
M - Martensitic Stainless SteelP - Machined PartAp - EnergyCd - Casting Defect
Cm - Kalling Etched Micrography by OMDf - Void

+1 more from this case →