Ferrous Alloys

3 cases · 21 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Application: Ship Condition: Corrosion Capture method: Scanning Electron Microscope clear all

Ferrous Alloys — sub-branches

Carbon Steel 2High Alloy Steel 1

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Fracture surface aspect at the scanning electron microscopy (SEM) of the clamp OD, showing different planes of propagation of the fracture.
42
VIEW
ML00171 / Feb.2021
Corrosion Fatigue of U Bolt Pipe Clamp
M - Low Carbon SteelP - BoltAp - ShipCd - Corrosion Fatigue
Cm - Fractography by SEMDf - Fracture
Micrography of the seam welded joint, autogenous. The localized dissolution occurrs exactly at the weld metal that presents a bainitic structure and Vickers (100g) microhardness values about 230HV, compared to the heat affected zone presenting average of 202 HV and the base metal presenting average of 180HV.
59
VIEW
ML00140 / May.2019
Preferential Corrosion of Pipe Seam Weld
M - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Cm - Nital Etched Micrography by SEMDf - Welded Joint
Corroded spots (shallow pits full of products) at the spring surface.
80
VIEW
ML00137 / Mar.2021
Brittle Fracture of a 15-5 PH Valve Spring
M - Precipitation Hardened Stainless SteelP - SpringAp - Oil and GasCd - Brittle Behavior
Cm - Surface Aspect by SEMDf - Corrosion

More from these cases

ML00171 — Corrosion Fatigue of U Bolt Pipe ClampM - Low Carbon SteelP - BoltAp - ShipCd - Corrosion Fatigue
Detail by scanning electron microscop of the clamp surface showing several cracks, parallel. In this image the cracks appear horizontal, but the photo was taken with the axis of the clamp in the vertical direction which means that the cracks are transverse to the axis.
41
VIEW
ML00171 / Feb.2021
Corrosion Fatigue of U Bolt Pipe Clamp
M - Low Carbon SteelP - BoltAp - ShipCd - Corrosion Fatigue
Cm - Surface Aspect by SEMDf - Multiple cracks
Detailed aspect of the previous figure showing the parallel cracks, transverse to the axis.
37
VIEW
ML00171 / Feb.2021
Corrosion Fatigue of U Bolt Pipe Clamp
M - Low Carbon SteelP - BoltAp - ShipCd - Corrosion Fatigue
Cm - Surface Aspect by SEMDf - Multiple cracks
Detail by scanning electron microscopy of the pits in the metallographic longitudinal section of the clamp, at the surface (left side of the image). There are cracks emanating from the pits.
27
VIEW
ML00171 / Feb.2021
Corrosion Fatigue of U Bolt Pipe Clamp
M - Low Carbon SteelP - BoltAp - ShipCd - Corrosion Fatigue
Cm - Nital Etched Micrography by SEMDf - Crack
Detail by scanning electron microscopy of the cracks emanating from the pits in the metallographic longitudinal section of the clamp, at the surface (left side of the image).
25
VIEW
ML00171 / Feb.2021
Corrosion Fatigue of U Bolt Pipe Clamp
M - Low Carbon SteelP - BoltAp - ShipCd - Corrosion Fatigue
Cm - Micrography by SEMDf - Crack
Metallographic aspect by scanning electron microscopy of one secondary cracking, paralell to the fracture surface, growthing with an irregular path and transgranular morphologyy.
28
VIEW
ML00171 / Feb.2021
Corrosion Fatigue of U Bolt Pipe Clamp
M - Low Carbon SteelP - BoltAp - ShipCd - Corrosion Fatigue
Cm - Micrography by SEMDf - Corrosion Cracking

+3 more from this case →

ML00140 — Preferential Corrosion of Pipe Seam WeldM - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Micrography at the scanning electron microscopy showing the deposits inside the crevice. The microanalysis by EDS revealed the presence of Fe, O, as well as Cl and S.
35
VIEW
ML00140 / May.2019
Preferential Corrosion of Pipe Seam Weld
M - Low Carbon SteelP - Longitudinal Seam Welded PipeAp - ShipCd - Preferential Dissolution
Cm - Micrography by SEMDf - Corrosion
ML00137 — Brittle Fracture of a 15-5 PH Valve SpringM - Precipitation Hardened Stainless SteelP - SpringAp - Oil and GasCd - Brittle Behavior
Corroded spots (shallow pits full of products) at the spring surface.
75
VIEW
ML00137 / Mar.2021
Brittle Fracture of a 15-5 PH Valve Spring
M - Precipitation Hardened Stainless SteelP - SpringAp - Oil and GasCd - Brittle Behavior
Cm - Surface Aspect by SEMDf - Corrosion
The scanning electron microscopy image presents the surface of the spring (top of the figure) where it was broken (the fracture is in the bottom of the figure). It is possible to see that there is a product at the surface and the material presents intergranular fracture, suggesting there was a hydrogen embrittlement effect. Important to observe that the material does not present pits.
58
VIEW
ML00137 / Mar.2021
Brittle Fracture of a 15-5 PH Valve Spring
M - Precipitation Hardened Stainless SteelP - SpringAp - Oil and GasCd - Brittle Behavior
Cm - Fractography by SEMDf - At the Surface
The scanning electron microscopy image presents the fracture surface at the fracture initiation point. The fracture is intergranular.
54
VIEW
ML00137 / Mar.2021
Brittle Fracture of a 15-5 PH Valve Spring
M - Precipitation Hardened Stainless SteelP - SpringAp - Oil and GasCd - Brittle Behavior
Cm - Fractography by SEMDf - Intergranular Fracture
Image detail presenting the intergranular fracture surface at the fracture initiation point.
46
VIEW
ML00137 / Mar.2021
Brittle Fracture of a 15-5 PH Valve Spring
M - Precipitation Hardened Stainless SteelP - SpringAp - Oil and GasCd - Brittle Behavior
Cm - Fractography by SEMDf - Intergranular Fracture
Fracture micromechanism changing from intergranular to transgranular, as the fracture is propagating.
45
VIEW
ML00137 / Mar.2021
Brittle Fracture of a 15-5 PH Valve Spring
M - Precipitation Hardened Stainless SteelP - SpringAp - Oil and GasCd - Brittle Behavior
Cm - Fractography by SEMDf - Fracture

+4 more from this case →