Optical Microscope

3 cases · 31 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Microstructure: Bainite Standard: AISI clear all

Optical Microscope — sub-branches

As polished micrography 2Micrography by OM 2Nital Etched Micrography by OM 27

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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
Micrography of the 4130 steel, normalized and tempered. The structure is sligthly banded (segregated) and the average hardness level is 20 HRc.
92
VIEW
ML00102 / May.2018
AISI 4130 Forging Welded and Overlaid
M - Low Alloy SteelP - CladdingAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Base Metal
Micrography of a longitudinal section of the pin, in the center. The low carbon content of the steel in the center of the pin makes the structure bainitic even though it was quenched and tempered after carburizing.
80
VIEW
ML00081 / Aug.2017
Hydrogen Cracking of a Chromium Plated Carburized Pin
M - Low Alloy for Thermochemical TreatmentP - Chromium PlatedAp - AutomotiveCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - In the Center of the Thickness

More from these cases

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
Shaft microstructure in the longitudinal section, showing aligned segregations typical of the material forming.
31
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 - Longitudinal Section

+4 more from this case →

ML00102 — AISI 4130 Forging Welded and OverlaidM - Low Alloy SteelP - CladdingAp - Oil and GasCd - Welding
Micrography of the 4130 steel, normalized and tempered. The microstructure is bainitic.
88
VIEW
ML00102 / May.2018
AISI 4130 Forging Welded and Overlaid
M - Low Alloy SteelP - CladdingAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Base Metal
Micrographic detail of the bainitic structure of the 4130 steel, normalized and tempered.
87
VIEW
ML00102 / May.2018
AISI 4130 Forging Welded and Overlaid
M - Low Alloy SteelP - CladdingAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Bainite
Micrography of the tubular 4130 forging at the heat affected zone (HAZ) of the Inconel overlay (white because it was not etched with the Nital). The structure is ferritic/bainitic because the overlay was conducted in two layers, and all the HAZ was reheated during welding.
66
VIEW
ML00102 / May.2018
AISI 4130 Forging Welded and Overlaid
M - Low Alloy SteelP - CladdingAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Heat Affected Zone
Micrography of the tubular 4130 forging at the heat affected zone (HAZ) of the Inconel overlay (white because it was not etched with the Nital). The structure is ferritic/bainitic because the overlay was conducted in two layers, and all the HAZ was reheated during welding.
61
VIEW
ML00102 / May.2018
AISI 4130 Forging Welded and Overlaid
M - Low Alloy SteelP - CladdingAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Heat Affected Zone
Micrographic detail of the bainitic heat affected zone (HAZ) of 4130 forging at the Inconel overlay.
50
VIEW
ML00102 / May.2018
AISI 4130 Forging Welded and Overlaid
M - Low Alloy SteelP - CladdingAp - Oil and GasCd - Welding
Cm - Nital Etched Micrography by OMDf - Bainitic Ferrite

+6 more from this case →

ML00081 — Hydrogen Cracking of a Chromium Plated Carburized PinM - Low Alloy for Thermochemical TreatmentP - Chromium PlatedAp - AutomotiveCd - Hydrogen Embrittlement
Micrographic detail of the bainitic structure in the center of the pin, that was quenched and tempered after carburizing.
75
VIEW
ML00081 / Aug.2017
Hydrogen Cracking of a Chromium Plated Carburized Pin
M - Low Alloy for Thermochemical TreatmentP - Chromium PlatedAp - AutomotiveCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Bainite
Micrography of a longitudinal section of the pin, at the surface. The pin was carburized, quenched and tempered (yellow diffuse layer at the surface, 0.5 mm of extension) and a white layer of hard chromium plating is evident.
108
VIEW
ML00081 / Aug.2017
Hydrogen Cracking of a Chromium Plated Carburized Pin
M - Low Alloy for Thermochemical TreatmentP - Chromium PlatedAp - AutomotiveCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Carburized Layer
Micrographic detail a longitudinal section of the pin, at the surface, showing the case hardened. The pin carburized, quenched and tempered structure presents a gradient of carbon content and consequently a gradient of martensitic structure and hardness. Close to the surface the hardness level is 742 HV1 .
87
VIEW
ML00081 / Aug.2017
Hydrogen Cracking of a Chromium Plated Carburized Pin
M - Low Alloy for Thermochemical TreatmentP - Chromium PlatedAp - AutomotiveCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - At the Surface
Micrographic detail of the high hardness martensitic structure at the surface of the pin, that was quenched and tempered after carburizing.
67
VIEW
ML00081 / Aug.2017
Hydrogen Cracking of a Chromium Plated Carburized Pin
M - Low Alloy for Thermochemical TreatmentP - Chromium PlatedAp - AutomotiveCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Martensite
Micrography that presents a secondary cracking (adjacent to the broken surface) propagating 500 microns from the surface, where there is a white layer of hard chromium .
78
VIEW
ML00081 / Aug.2017
Hydrogen Cracking of a Chromium Plated Carburized Pin
M - Low Alloy for Thermochemical TreatmentP - Chromium PlatedAp - AutomotiveCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Carburized Layer

+3 more from this case →