Atlas

4 cases · 8 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

ML00156 / Jan.2020
Antique Silver Plated Decorative Piece
M - BrassP - Decorative PieceAp - OrnamentalCd - Non Destructive Examination
Cm - Surface Aspect by SEMDf - Casting defects
Scanning electron microscopy image of the chromium plated cylinder surface, presenting deposits and localized dissolution under deposits. There are different stages of corrosion in this region, observed in low magnification. Small areas of attack and a shallow pitting with deposits that were analyzed by EDS and revealed the presence of S.
903
ML00128 / Apr.2018
MIC of a Stored Hydraulic Cylinder
M - Low Carbon SteelP - Chromium PlatedAp - OffshoreCd - Localized Dissolution
Cm - Surface Aspect by SEMDf - Localized Corrosion
Fractographic analysis by scanning electron microscopy of the stud fracture surface after opening the cracks.  Brittle intergranular morphology with dimples and quasecleavage micromechanisms indicate that the internal cracks, intergranular, occurred by a hydrogen embrittlement effect during electroplating, and the ductile aspects are probably associated to overloading during torque.
517
ML00127 / May.2018
Hydrogen Cracks of Cadmium Plated Studs
M - Low Alloy Medium Carbon QTP - Allen StudAp - Oil and GasCd - Hydrogen Embrittlement
Cm - Fractography by SEMDf - Fracture
Aspect of the fracture surface of the bolt, after cleaning with a  plastic brush.  Although there is a layer of oxides it is possible to see the intergranular morphology of the fracture, typical of a hydrogen embrittlement mechanism.
1154
ML00126 / Mar.2018
Hydrogen Fracture of Subsea Allen Bolts
M - Low Alloy Medium Carbon QTP - Coated ProductAp - SubseaCd - Hydrogen Embrittlement
Cm - Fractography by SEMDf - Intergranular Fracture

More from these cases

ML00128 — MIC of a Stored Hydraulic CylinderM - Low Carbon SteelP - Chromium PlatedAp - OffshoreCd - Localized Dissolution
ML00128 / Apr.2018
MIC of a Stored Hydraulic Cylinder
M - Low Carbon SteelP - Chromium PlatedAp - OffshoreCd - Localized Dissolution
Cm - Surface Aspect by SEMDf - Corrosion
ML00128 / Apr.2018
MIC of a Stored Hydraulic Cylinder
M - Low Carbon SteelP - Chromium PlatedAp - OffshoreCd - Localized Dissolution
Cm - Surface Aspect by SEMDf - Corrosion
ML00127 — Hydrogen Cracks of Cadmium Plated StudsM - Low Alloy Medium Carbon QTP - Allen StudAp - Oil and GasCd - Hydrogen Embrittlement
ML00127 / May.2018
Hydrogen Cracks of Cadmium Plated Studs
M - Low Alloy Medium Carbon QTP - Allen StudAp - Oil and GasCd - Hydrogen Embrittlement
Cm - Fractography by SEMDf - Intergranular Cracking
ML00126 — Hydrogen Fracture of Subsea Allen BoltsM - Low Alloy Medium Carbon QTP - Coated ProductAp - SubseaCd - Hydrogen Embrittlement
Detailed aspect of the fracture surface of the bolt, evidencing the intergranular morphology of the fracture (although with an oxide scale), typical of a hydrogen embrittlement mechanism.
114
ML00126 / Mar.2018
Hydrogen Fracture of Subsea Allen Bolts
M - Low Alloy Medium Carbon QTP - Coated ProductAp - SubseaCd - Hydrogen Embrittlement
Cm - Fractography by SEMDf - Intergranular Fracture