Microstructure

14 cases · 41 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Microstructure: Martensite Capture method: Optical Microscope clear all

Microstructure — sub-branches

Acicular Ferrite 1Bainite 2Bainitic Ferrite 1Bainitic Martensitic 2Banded Structure 1Coarse Structure 1Coating Layer 5Decarburized Surface 1Ferrite 1Ferrite and Pearlite 4Martensite 19Strain hardened pearlite 1Tempered Martensite 1Uniform Structure 1

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Micrography presenting a tempered martensitic microstructure, with light etch in segregated bands.
74
VIEW
ML00182 / Jul.2022
Brittle Fracture of a LAS Fixing Rod
M - Low Alloy Medium Carbon QTP - StemAp - Mechanical IndustryCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Tempered Martensite
Micrographic detail of the case hardened martensitic structure, close to the surface, with a microhardness level of about 600 Vickers (load 0.3kg).
70
VIEW
ML00181 / Apr.2022
Wear of a Carburized Hypoid Gear
M - Low Alloy for Thermochemical TreatmentP - Pinion-crown assemblyAp - ShipCd - Wear
Cm - Nital Etched Micrography by OMDf - Martensite
Micrographic detail of spring surface, showing the pits full of corrosion deposits and a small decarburized layer (probably from the manufacturing processes).
30
VIEW
ML00172 / Mar.2021
Brittle Fracture of a LAS Valve Spring
M - Low Alloy Medium Carbon QTP - SpringAp - Oil and GasCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Decarburized Surface
Micrographic detail of the weld metal with islands of a coarse ferritic structure, degradated (recristalized) from an acicular morphology during to the long heat treatment cycle in high temperature. The post welding heat treatment (PWHT) was conducted during 12 hours at 640°C.
700
VIEW
ML00129 / Apr.2018
Non qualified WPS for High Strength Steel
M - Low Alloy Medium Carbon QTP - Welded Testpiece for QualificationAp - Oil and GasCd - Non qualified
Cm - Nital Etched Micrography by OMDf - Coarse Structure
Micrographic detail of a longitudinal section of a 4 mm diameter wire, presenting an aligned and highly strained pearlitic structure. Base metal.
386
VIEW
ML00113 / Jan.2018
Autogenous Weld of a Carbon Steel Wire
M - Medium Carbon SteelP - WireAp - OffshoreCd - Welding
Cm - Nital Etched Micrography by OMDf - Strain hardened pearlite
Micrography of the thermal spray (TS) layer showing the different alloys, gray oxides and black voids. The Ni base TS alloy is of a yellow colour at the interface with the shaft substrate (in the left). The Cr base TS alloy appears white, similar to the shaft substrate. Longitudinal section of the shaft.
42
VIEW
ML00108 / Dec.2017
Thermal Spray Layer in a Pinion Shaft
M - High Strength Low AlloyP - ShaftAp - EngineCd - Coating Defect
Cm - As polished micrographyDf - Coating Layer
Tempered martensitic microstructure in the transverse section of the nut, in the center. The material presented 29 HRc that is typical of a quenched and tempered steel.
30
VIEW
ML00099 / Jan.2018
Forging Defect in a Cadmium Plated Nut
M - Medium Carbon SteelP - NutAp - PipingCd - Fabrication Defect
Cm - Nital Etched Micrography by OMDf - Martensite
Micrography of a longitudinal section of the housing presenting a uniform tempered martensitic structure. The material presented a thickness about 2.5 mm in the region where the cracking started.
52
VIEW
ML00093 / Sep.2017
MIC of a Drilling Tool
M - Low Alloy Medium Carbon QTP - Heat Treated PartAp - O&G Well DrillingCd - Brittle Behavior
Cm - Nital Etched Micrography by OMDf - Uniform Structure

More from these cases

ML00181 — Wear of a Carburized Hypoid GearM - Low Alloy for Thermochemical TreatmentP - Pinion-crown assemblyAp - ShipCd - Wear
Micrography of the core structure, in the center of layer, with a microhardness level of about 220 Vickers (load 0.3kg).
58
VIEW
ML00181 / Apr.2022
Wear of a Carburized Hypoid Gear
M - Low Alloy for Thermochemical TreatmentP - Pinion-crown assemblyAp - ShipCd - Wear
Cm - Nital Etched Micrography by OMDf - Bainitic Martensitic
Wear of a Carburized Hypoid Gear
3
VIEW
ML00181 / Apr.2022
Wear of a Carburized Hypoid Gear
M - Low Alloy for Thermochemical TreatmentP - Pinion-crown assemblyAp - ShipCd - Wear
Cm - Nital Etched Micrography by OMDf - Bainitic Martensitic
ML00172 — Brittle Fracture of a LAS Valve SpringM - Low Alloy Medium Carbon QTP - SpringAp - Oil and GasCd - Brittle Fracture
Micrographic detail of the transverse section of the spring wire, martensitic.
24
VIEW
ML00172 / Mar.2021
Brittle Fracture of a LAS Valve Spring
M - Low Alloy Medium Carbon QTP - SpringAp - Oil and GasCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Martensite
Micrographic detail of the martensitic structure, uniform through thickness.
17
VIEW
ML00172 / Mar.2021
Brittle Fracture of a LAS Valve Spring
M - Low Alloy Medium Carbon QTP - SpringAp - Oil and GasCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Martensite
ML00129 — Non qualified WPS for High Strength SteelM - Low Alloy Medium Carbon QTP - Welded Testpiece for QualificationAp - Oil and GasCd - Non qualified
Micrographic detail of the base metal structure, quenched and tempered martensite. The base metal adopted in the test coupon presented a hardness level of 217HB (Brinell hardness of the certificate) and after the PWHT cycle the measured base metal hardness is 224 HV10.
51
VIEW
ML00129 / Apr.2018
Non qualified WPS for High Strength Steel
M - Low Alloy Medium Carbon QTP - Welded Testpiece for QualificationAp - Oil and GasCd - Non qualified
Cm - Nital Etched Micrography by OMDf - Martensite
Micrographic detail of the heat affected zone at the face of the joint, close to the fusion line. The structure is martensitic but the previous austenite grain boundary was not large. 248HV10.
47
VIEW
ML00129 / Apr.2018
Non qualified WPS for High Strength Steel
M - Low Alloy Medium Carbon QTP - Welded Testpiece for QualificationAp - Oil and GasCd - Non qualified
Cm - Nital Etched Micrography by OMDf - Martensite
Micrographic detail of the weld metal at the face of the joint showing the acicular ferrite structure. The hardness level in this region is about 250HV10.
41
VIEW
ML00129 / Apr.2018
Non qualified WPS for High Strength Steel
M - Low Alloy Medium Carbon QTP - Welded Testpiece for QualificationAp - Oil and GasCd - Non qualified
Cm - Nital Etched Micrography by OMDf - Acicular Ferrite
Micrographic detail of the heat affected zone at the root of the joint, submitted to several welding reheating cycles. The structure is martensitic with a refined previous austenite structure.
38
VIEW
ML00129 / Apr.2018
Non qualified WPS for High Strength Steel
M - Low Alloy Medium Carbon QTP - Welded Testpiece for QualificationAp - Oil and GasCd - Non qualified
Cm - Nital Etched Micrography by OMDf - Martensite
Micrographic detail of the weld metal at the root of the joint showing a mixture of acicular structure with equiaxial ferritic structure. The hardness level in this region is about 231HV10.
34
VIEW
ML00129 / Apr.2018
Non qualified WPS for High Strength Steel
M - Low Alloy Medium Carbon QTP - Welded Testpiece for QualificationAp - Oil and GasCd - Non qualified
Cm - Nital Etched Micrography by OMDf - Ferrite
ML00113 — Autogenous Weld of a Carbon Steel WireM - Medium Carbon SteelP - WireAp - OffshoreCd - Welding
Micrographic detail of a longitudinal section of a 4 mm diameter wire, at the heat affected zone created by the autogenous welding, presenting a tempered martensitic structure.
23
VIEW
ML00113 / Jan.2018
Autogenous Weld of a Carbon Steel Wire
M - Medium Carbon SteelP - WireAp - OffshoreCd - Welding
Cm - Nital Etched Micrography by OMDf - Martensite
Micrographic detail of a longitudinal section of a 4 mm diameter wire, in the center of the autogenously welded joint, presenting a tempered martensitic structure.
17
VIEW
ML00113 / Jan.2018
Autogenous Weld of a Carbon Steel Wire
M - Medium Carbon SteelP - WireAp - OffshoreCd - Welding
Cm - Nital Etched Micrography by OMDf - Martensite
ML00108 — Thermal Spray Layer in a Pinion ShaftM - High Strength Low AlloyP - ShaftAp - EngineCd - Coating Defect
Micrographic detail, as polished in a longitudinal section, of the interface between the shaft substrate and the thermal spray layer. In the left it is the shaft substrate also presenting parts of aligned inclusions (gray). In the center it is the Ni base TS alloy and in the right it is the Cr base TS alloy. There are also black voids and grey oxides.
33
VIEW
ML00108 / Dec.2017
Thermal Spray Layer in a Pinion Shaft
M - High Strength Low AlloyP - ShaftAp - EngineCd - Coating Defect
Cm - As polished micrographyDf - Coating Layer
Micrography of the interface between the shaft surface and the thermal spray layer. The shaft steel presents a quenched and tempered structure. Longitudinal section.
32
VIEW
ML00108 / Dec.2017
Thermal Spray Layer in a Pinion Shaft
M - High Strength Low AlloyP - ShaftAp - EngineCd - Coating Defect
Cm - Nital Etched Micrography by OMDf - Coating Layer
Micrographic detail of the interface between the shaft surface and the thermal spray layer. The shaft steel presents a quenched and tempered structure. Longitudinal section.
33
VIEW
ML00108 / Dec.2017
Thermal Spray Layer in a Pinion Shaft
M - High Strength Low AlloyP - ShaftAp - EngineCd - Coating Defect
Cm - Nital Etched Micrography by OMDf - Coating Layer
Micrographic detail of the interface between the shaft surface and the thermal spray layer. The shaft steel presents a quenched and (over) tempered structure. Longitudinal section.
35
VIEW
ML00108 / Dec.2017
Thermal Spray Layer in a Pinion Shaft
M - High Strength Low AlloyP - ShaftAp - EngineCd - Coating Defect
Cm - Nital Etched Micrography by OMDf - Coating Layer
Micrography of the shaft in the center of the thickness. Bainitic structure with martensite in the segregated bands. Longitudinal section.
29
VIEW
ML00108 / Dec.2017
Thermal Spray Layer in a Pinion Shaft
M - High Strength Low AlloyP - ShaftAp - EngineCd - Coating Defect
Cm - Nital Etched Micrography by OMDf - Bainite

+3 more from this case →

ML00099 — Forging Defect in a Cadmium Plated NutM - Medium Carbon SteelP - NutAp - PipingCd - Fabrication Defect
Ferritic-bainitic microstructure in the transverse section of the nut, at the surface where the cadmium plate is also evident. The nut surface presents a decarburized layer and the lap entrapped oxides.
30
VIEW
ML00099 / Jan.2018
Forging Defect in a Cadmium Plated Nut
M - Medium Carbon SteelP - NutAp - PipingCd - Fabrication Defect
Cm - Nital Etched Micrography by OMDf - Bainitic Ferrite