Optical Microscope

9 cases · 95 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

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Optical Microscope — sub-branches

Eletrolytically Etched Micrography by OM 9Kalling Etched Micrography by OM 22Keller Etched Micrography by OM 21Micrography by OM 2Micrography by OM using A262 Method A 4NaOH Electrolytic Etched Micro 17Nital Etched Micrography by OM 20

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Micrography of the cast rim, base metal, in the as polished condition, showing the dendrites of alpha aluminum and interdendritic eutectic Si/alpha, silicon particles in a coalesced condition that sugegsts a solution annealed treatment.
119
VIEW
ML00070 / Jan.2019
Automotive Light Alloy Wheel Repaired By Welding
M - Aluminum Silicon MagnesiumP - RimAp - AutomotiveCd - Removed From Service
Cm - Micrography by OMDf - Base Metal
Micrography of a longitudinal section of the pipe AA 3003. Granular structure that reveals the forming direction and dispersed particles.
229
VIEW
ML00059 / Feb.2018
Intergranular Corrosion of Aluminum Piping
M - Aluminum ManganeseP - Welded JointAp - Chemical IndustryCd - Intergranular Corrosion
Cm - Keller Etched Micrography by OMDf - Base Metal Left Side
Micrography of the base metal presenting a banded microstructure in the longitudinal section of the pipe.
51
VIEW
ML00066 / May.2017
GMAW Welded Joint in 9%Ni Alloy Steel
M - Nickel Alloy SteelP - Welded Testpiece for QualificationAp - PipelineCd - Welding
Cm - Nital Etched Micrography by OMDf - Base Metal
Micrography of a longitudinal section of the pipe showing that the carbon steel pipe is slightly banded and there is a decarburized layer at the solid solution welded interface. The stainless steel structure (in the right side of the figure) is not revealed using the Nital etch.
124
VIEW
ML00056 / May.2018
Seamless Tube Externally Cladded with SS
M - Carbon Steel / Stainless SteelP - CladdingAp - Pulp and PaperCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Longitudinal Section
Original casting base metal presenting a coarse martensitic structure with a small amount of delta ferrite.
50
VIEW
ML00055 / Apr.2017
CA6NM Blade Remanufactured by Welding
M - Martensitic Stainless SteelP - Remanufacture by WeldingAp - EnergyCd - Removed From Service
Cm - Kalling Etched Micrography by OMDf - Base Metal Left Side
Base metal micrographic detail presenting a tempered martensitic microstructure.
27
VIEW
ML00045 / Aug.2017
Subsea Tubular F6NM Martensitic SS
M - Martensitic Stainless SteelP - Fabrication WeldAp - OffshoreCd - Welding
Cm - Kalling Etched Micrography by OMDf - Base Metal
Micrography of the plate material presenting a granular austenitic structure, free from precipitation.
122
VIEW
ML00051 / Apr.2020
Chloride SCC of 316 Heat Exchanger Plate
M - Austenitic Stainless SteelP - Heat Exchanger PartAp - FPSOCd - Stress Corrosion
Cm - Eletrolytically Etched Micrography by OMDf - Austenite
The micrography shows the region underbead, of the tube HAZ, responsible for the hydrogen cracking (fracture in the right side of the photo - black). The hardness of the HAZ is about 600 HV.
55
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 - Cracking

More from these cases

ML00070 — Automotive Light Alloy Wheel Repaired By WeldingM - Aluminum Silicon MagnesiumP - RimAp - AutomotiveCd - Removed From Service
Micrography of the cast rim, base metal, showing the dendrites of alpha aluminum and interdendritic eutectic Si/alpha, silicon particles in a coalesced condition that suggests a solution annealed treatment. After etching it is possible to identify a transgranular precipitation (aging) and a dark FeSiAl phase (neddles).
87
VIEW
ML00070 / Jan.2019
Automotive Light Alloy Wheel Repaired By Welding
M - Aluminum Silicon MagnesiumP - RimAp - AutomotiveCd - Removed From Service
Cm - Keller Etched Micrography by OMDf - Base Metal
Micrographic detail of the cast rim, base metal, in the as polished condition, showing the dendrites of alpha aluminum and interdendritic eutectic Si/alpha, silicon particles in a coalesced condition that sugegsts a solution annealed treatment.
74
VIEW
ML00070 / Jan.2019
Automotive Light Alloy Wheel Repaired By Welding
M - Aluminum Silicon MagnesiumP - RimAp - AutomotiveCd - Removed From Service
Cm - Micrography by OMDf - Base Metal
Micrographic detail of the cast rim, base metal, showing the dendrites of alpha aluminum and interdendritic eutectic Si/alpha, silicon particles in a coalesced condition that suggests a solution annealed treatment. After etching it is possible to identify a transgranular precipitation (aging) and a dark FeSiAl phase (neddles).
62
VIEW
ML00070 / Jan.2019
Automotive Light Alloy Wheel Repaired By Welding
M - Aluminum Silicon MagnesiumP - RimAp - AutomotiveCd - Removed From Service
Cm - Keller Etched Micrography by OMDf - Base Metal
Low magnification micrography of the welded region, showing the base metal in the bottom, the fusion zone (between the liquidus and solidus temperatures) in the center and the weld metal in the top. There are pores close to the weld metal and in the fusion zone the interdendritic space was melted and the eutectic morphology was changed.
64
VIEW
ML00070 / Jan.2019
Automotive Light Alloy Wheel Repaired By Welding
M - Aluminum Silicon MagnesiumP - RimAp - AutomotiveCd - Removed From Service
Cm - Keller Etched Micrography by OMDf - Weld Repair
The cast material that presents for the base metal a coalesced silicon particles in the interdendritic space and intragranular precipitation shows a solution effect at the heat affected zone.
52
VIEW
ML00070 / Jan.2019
Automotive Light Alloy Wheel Repaired By Welding
M - Aluminum Silicon MagnesiumP - RimAp - AutomotiveCd - Removed From Service
Cm - Keller Etched Micrography by OMDf - Heat Affected Zone

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ML00059 — Intergranular Corrosion of Aluminum PipingM - Aluminum ManganeseP - Welded JointAp - Chemical IndustryCd - Intergranular Corrosion
Micrographic detail of a longitudinal section of the pipe AA 3003. Granular structure and dispersed particles.
199
VIEW
ML00059 / Feb.2018
Intergranular Corrosion of Aluminum Piping
M - Aluminum ManganeseP - Welded JointAp - Chemical IndustryCd - Intergranular Corrosion
Cm - Keller Etched Micrography by OMDf - Base Metal Left Side
Micrography of a longitudinal section of the pipe AA 6063. Granular structure and dispersed particles.
169
VIEW
ML00059 / Feb.2018
Intergranular Corrosion of Aluminum Piping
M - Aluminum ManganeseP - Welded JointAp - Chemical IndustryCd - Intergranular Corrosion
Cm - Keller Etched Micrography by OMDf - Base Metal Right Side
Micrography of the Fusion Line of the AA 3003 pipe, presenting a narrow HAZ.
127
VIEW
ML00059 / Feb.2018
Intergranular Corrosion of Aluminum Piping
M - Aluminum ManganeseP - Welded JointAp - Chemical IndustryCd - Intergranular Corrosion
Cm - Keller Etched Micrography by OMDf - Fusion Line Left Side
Micrography of the Fusion Line of the AA 3003 pipe, presenting a narrow HAZ.
110
VIEW
ML00059 / Feb.2018
Intergranular Corrosion of Aluminum Piping
M - Aluminum ManganeseP - Welded JointAp - Chemical IndustryCd - Intergranular Corrosion
Cm - Keller Etched Micrography by OMDf - Fusion Line Left Side
Micrographic detail of the Fusion Line of the AA 3003 pipe, presenting a narrow HAZ.
93
VIEW
ML00059 / Feb.2018
Intergranular Corrosion of Aluminum Piping
M - Aluminum ManganeseP - Welded JointAp - Chemical IndustryCd - Intergranular Corrosion
Cm - Keller Etched Micrography by OMDf - Fusion Line Left Side

+9 more from this case →

ML00066 — GMAW Welded Joint in 9%Ni Alloy SteelM - Nickel Alloy SteelP - Welded Testpiece for QualificationAp - PipelineCd - Welding
Micrographic detail of a longitudinal section of the base metal presenting a quenched and tempered microstructure.
49
VIEW
ML00066 / May.2017
GMAW Welded Joint in 9%Ni Alloy Steel
M - Nickel Alloy SteelP - Welded Testpiece for QualificationAp - PipelineCd - Welding
Cm - Nital Etched Micrography by OMDf - Base Metal
Micrographic detail of the low temperature heat affected zone of the pipe. The intercritical temperature (IC) is evident in the decorated grain boundaries of the previous austenite.
42
VIEW
ML00066 / May.2017
GMAW Welded Joint in 9%Ni Alloy Steel
M - Nickel Alloy SteelP - Welded Testpiece for QualificationAp - PipelineCd - Welding
Cm - Nital Etched Micrography by OMDf - Heat Affected Zone
Micrography of the fusion line close to the cap pass (CP). The weld metal (non etched) is in the left side.
43
VIEW
ML00066 / May.2017
GMAW Welded Joint in 9%Ni Alloy Steel
M - Nickel Alloy SteelP - Welded Testpiece for QualificationAp - PipelineCd - Welding
Cm - Nital Etched Micrography by OMDf - Fusion Line
Micrography of the heat affected zone, a little far from the fusion line, close to the base metal.
40
VIEW
ML00066 / May.2017
GMAW Welded Joint in 9%Ni Alloy Steel
M - Nickel Alloy SteelP - Welded Testpiece for QualificationAp - PipelineCd - Welding
Cm - Nital Etched Micrography by OMDf - Heat Affected Zone
Micrographic detail of the fusion line in the center of the thickness, where the heat affected zone was reheated by the subsequent passes.
34
VIEW
ML00066 / May.2017
GMAW Welded Joint in 9%Ni Alloy Steel
M - Nickel Alloy SteelP - Welded Testpiece for QualificationAp - PipelineCd - Welding
Cm - Nital Etched Micrography by OMDf - Fusion Line

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ML00056 — Seamless Tube Externally Cladded with SSM - Carbon Steel / Stainless SteelP - CladdingAp - Pulp and PaperCd - Removed From Service
Micrography of a longitudinal section of the pipe showing the carbon steel pipe , internal.
122
VIEW
ML00056 / May.2018
Seamless Tube Externally Cladded with SS
M - Carbon Steel / Stainless SteelP - CladdingAp - Pulp and PaperCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Ferrite and Pearlite
Micrography of a longitudinal section of the pipe showing the stainless steel pipe , external.
99
VIEW
ML00056 / May.2018
Seamless Tube Externally Cladded with SS
M - Carbon Steel / Stainless SteelP - CladdingAp - Pulp and PaperCd - Removed From Service
Cm - Micrography by OM using A262 Method ADf - Austenite
Micrographic detail of the interface in the longitudinal section of the pipe showing the Vickers (300g) microhardness values, close to the interface in the carbon steel side and in the stainless steel side. Although the Nital etch does not allow to reveal the structure in the stainless steel side, the high hardness values show that the structure is different.
112
VIEW
ML00056 / May.2018
Seamless Tube Externally Cladded with SS
M - Carbon Steel / Stainless SteelP - CladdingAp - Pulp and PaperCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Longitudinal Section
Micrographic detail of the interface in the longitudinal section of the pipe showing the decarburized layer at the solid solution welded interface. The stainless steel structure (in the right side of the figure) is not revealed using the Nital etch.
80
VIEW
ML00056 / May.2018
Seamless Tube Externally Cladded with SS
M - Carbon Steel / Stainless SteelP - CladdingAp - Pulp and PaperCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Clad Interface
Micrography of the interface between the carbon steel that is strongly etched by the electrolytic oxalic acid (in the left side of the figure) and the stainless steel, in the longitudinal section of the pipe. There is a strain hardened layer very close to the interface, at the stainless steel side.
79
VIEW
ML00056 / May.2018
Seamless Tube Externally Cladded with SS
M - Carbon Steel / Stainless SteelP - CladdingAp - Pulp and PaperCd - Removed From Service
Cm - Micrography by OM using A262 Method ADf - Longitudinal Section

+2 more from this case →

ML00055 — CA6NM Blade Remanufactured by WeldingM - Martensitic Stainless SteelP - Remanufacture by WeldingAp - EnergyCd - Removed From Service
Inserted casting base metal presenting a coarse martensitic structure with a small amount of delta ferrite.
24
VIEW
ML00055 / Apr.2017
CA6NM Blade Remanufactured by Welding
M - Martensitic Stainless SteelP - Remanufacture by WeldingAp - EnergyCd - Removed From Service
Cm - Kalling Etched Micrography by OMDf - Base Metal Right Side
Micrography of the original casting blade at the fusion line of the welding with the insert casting. There is a refinement effect on the coarse base metal structure.
24
VIEW
ML00055 / Apr.2017
CA6NM Blade Remanufactured by Welding
M - Martensitic Stainless SteelP - Remanufacture by WeldingAp - EnergyCd - Removed From Service
Cm - Kalling Etched Micrography by OMDf - HAZ Left Side
Micrographic detail of the fusion line of the original casting blade welded to the insert casting. There is a refinement effect on the coarse base metal structure.
21
VIEW
ML00055 / Apr.2017
CA6NM Blade Remanufactured by Welding
M - Martensitic Stainless SteelP - Remanufacture by WeldingAp - EnergyCd - Removed From Service
Cm - Kalling Etched Micrography by OMDf - HAZ Left Side
Micrography of the inserted casting at the heat affected zone of the welding with the original casting. There is a refinement effect on the coarse base metal structure.
20
VIEW
ML00055 / Apr.2017
CA6NM Blade Remanufactured by Welding
M - Martensitic Stainless SteelP - Remanufacture by WeldingAp - EnergyCd - Removed From Service
Cm - Kalling Etched Micrography by OMDf - HAZ Right Side
Micrographic detail of the fusion line of the inserted casting welded to the original casting. There is a refinement effect on the coarse base metal structure.
15
VIEW
ML00055 / Apr.2017
CA6NM Blade Remanufactured by Welding
M - Martensitic Stainless SteelP - Remanufacture by WeldingAp - EnergyCd - Removed From Service
Cm - Kalling Etched Micrography by OMDf - HAZ Right Side

+2 more from this case →

ML00045 — Subsea Tubular F6NM Martensitic SSM - Martensitic Stainless SteelP - Fabrication WeldAp - OffshoreCd - Welding
Micrographic detail of the heat-affected zone close to the base metal.
29
VIEW
ML00045 / Aug.2017
Subsea Tubular F6NM Martensitic SS
M - Martensitic Stainless SteelP - Fabrication WeldAp - OffshoreCd - Welding
Cm - Kalling Etched Micrography by OMDf - Heat Affected Zone
Micrographic detail of the heat-affected zone close to the fusion line.
31
VIEW
ML00045 / Aug.2017
Subsea Tubular F6NM Martensitic SS
M - Martensitic Stainless SteelP - Fabrication WeldAp - OffshoreCd - Welding
Cm - Kalling Etched Micrography by OMDf - Heat Affected Zone
Micrographic detail of the tempered martesite weld metal close to the fusion line. The columnar grains can be observed .
22
VIEW
ML00045 / Aug.2017
Subsea Tubular F6NM Martensitic SS
M - Martensitic Stainless SteelP - Fabrication WeldAp - OffshoreCd - Welding
Cm - Kalling Etched Micrography by OMDf - Weld Metal
Micrography of the base metal showing a tempered martensitic microstructure.
29
VIEW
ML00045 / Aug.2017
Subsea Tubular F6NM Martensitic SS
M - Martensitic Stainless SteelP - Fabrication WeldAp - OffshoreCd - Welding
Cm - Kalling Etched Micrography by OMDf - Base Metal
Micrography of the heat-affected zone. The fusion line is in the right and the coarse structure of the base metal is refined at the heat affected zone.
28
VIEW
ML00045 / Aug.2017
Subsea Tubular F6NM Martensitic SS
M - Martensitic Stainless SteelP - Fabrication WeldAp - OffshoreCd - Welding
Cm - Kalling Etched Micrography by OMDf - Heat Affected Zone

+8 more from this case →

ML00051 — Chloride SCC of 316 Heat Exchanger PlateM - Austenitic Stainless SteelP - Heat Exchanger PartAp - FPSOCd - Stress Corrosion
Micrographic detail of the austenitic microstructure of the heat exchanger plate, free from carbides that suggest the adoption of a material in a solution annealed condition, although the high hardness level indicates cold working.
109
VIEW
ML00051 / Apr.2020
Chloride SCC of 316 Heat Exchanger Plate
M - Austenitic Stainless SteelP - Heat Exchanger PartAp - FPSOCd - Stress Corrosion
Cm - Eletrolytically Etched Micrography by OMDf - Austenite
Micrography presenting the transgranular morphology of the stress corrosion cracks of the austenitic plate. EDS analysis at the plate surface indicated high Cl peaks.
111
VIEW
ML00051 / Apr.2020
Chloride SCC of 316 Heat Exchanger Plate
M - Austenitic Stainless SteelP - Heat Exchanger PartAp - FPSOCd - Stress Corrosion
Cm - Eletrolytically Etched Micrography by OMDf - Corrosion Cracking
Micrographic detail of a branch transgranular crack typical of CSCC. Moreover, there is no evidence of intergranular precipitation.
99
VIEW
ML00051 / Apr.2020
Chloride SCC of 316 Heat Exchanger Plate
M - Austenitic Stainless SteelP - Heat Exchanger PartAp - FPSOCd - Stress Corrosion
Cm - Micrography by OM using A262 Method ADf - Corrosion Cracking
ML00052 — Cold Cracks in API 5CT L80 Tube Welded to a Structural PartM - Low Alloy SteelP - Seamless tubeAp - OffshoreCd - Welding Defect
Low carbon plate base metal presenting the ferritic perlitic structure.
55
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 - Base Metal
High Strenght Low Alloy steel tube, base metal, presenting the bainitic structure.
54
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 - Base Metal
Micrography of the low carbon steel plate at the fusion line, presenting a bainitic structure at the HAZ and ferritic structure in the weld metal.
82
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
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 the weld metal in the center of the fillet showing a 100% acicular ferrite that is a microestructure of a high strenght steel, evidenced the effect of the dilution of the tube chemistry in the weld metal.
40
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 - Weld Metal

+1 more from this case →