ALLOY

4 cases · 15 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Microstructure: Austenite Capture method: Scanning Electron Microscope clear all

ALLOY — sub-branches

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Microscopical aspect by scanning electron microscopy (SEM) of the external surface of a drilling tool in a position that presented localized deposits and corrosion under deposit. The deep corrosion in a short time is only possible associated to the biological growth and aggressive environment generated by the microorganisms metabolites - Microbiologically Induced Corrosion (MIC).
104
VIEW
ML00135 / May.2018
MIC of a Non Magnetic Drilling Tool
M - High Mn Austenitic SteelP - Tubular ForgingAp - O&G Well DrillingCd - Pitting Corrosion
Cm - Surface Aspect by SEMDf - Localized Deposits
Image by scanning electron microscopy of the metallurgically bonded interface of the internally cladded pipe. It is a seamless pipe in a low alloy steel X70 cladded by welding overlay of Alloy 625 (by automatic GTAW process). The region is a detail of the interface inside the Ni alloy weld metal, presenting columnar grains and intragranular preciptation. The pipe was heat treated before bending (solution annealing) and after bending (quenching and tempering to meet X70 grade). The microhardness of this region is higher than the value obtained out of this region, in the overlay.
656
VIEW
ML00132 / May.2018
Seamless Pipe Overlaid with Alloy 625
M - LAS / Ni AlloyP - Seamless PipeAp - Oil and GasCd - Welding
Cm - Electrolytic Etch Micrography by SEMDf - Clad Interface
Scanning electron microscopy image of the external surface of the line at the cracking position showing multiple cracks, branched, transverse to the line axis.
79
VIEW
ML00095 / Sep.2017
MIC of a Riser Control Line
M - Austenitic Stainless SteelP - Fabrication WeldAp - Oil and GasCd - Brittle Behavior
Cm - Surface Aspect by SEMDf - External Surface
Transgranular brittle aspect of the stud fracture surface. Evidences of hydrogen embrittlement.
965
VIEW
ML00075 / Jun.2018
Hydrogen Cracking of IN 718 Subsea Fasteners
M - NiCrFe AlloyP - StudAp - SubseaCd - Hydrogen Embrittlement
Cm - Fractography by SEMDf - Secondary Cracks

More from these cases

ML00135 — MIC of a Non Magnetic Drilling ToolM - High Mn Austenitic SteelP - Tubular ForgingAp - O&G Well DrillingCd - Pitting Corrosion
Microscopical aspect by scanning electron microscopy (SEM) of the external surface of a drilling tool in a position that presented localized deposits and corrosion under deposit. It is possible to see that the strain hardened surface was etched by the aggressive metabolites of the microorganisms.
90
VIEW
ML00135 / May.2018
MIC of a Non Magnetic Drilling Tool
M - High Mn Austenitic SteelP - Tubular ForgingAp - O&G Well DrillingCd - Pitting Corrosion
Cm - Surface Aspect by SEMDf - Localized Corrosion
ML00132 — Seamless Pipe Overlaid with Alloy 625M - LAS / Ni AlloyP - Seamless PipeAp - Oil and GasCd - Welding
Image by scanning electron microscopy of the interface of the internally cladded pipe. It is a seamless pipe in low alloy steel X70 overlaid with Alloy 625 (by automatic GTAW process). The region is a detail in the side of the Ni alloy weld metal, presenting transgranular precipitation. The pipe was heat treated before bending (solution annelaing) and after bending (quenching and tempering to meet X70 grade). The microhardness of this region is higher than the value obtained out of this region, in the overlay.
42
VIEW
ML00132 / May.2018
Seamless Pipe Overlaid with Alloy 625
M - LAS / Ni AlloyP - Seamless PipeAp - Oil and GasCd - Welding
Cm - Electrolytic Etch Micrography by SEMDf - Clad Interface
Image by scanning electron microscopy of the interface of the internally cladded pipe, seamless low alloy steel X70 overlaid with Alloy 625 (by automatic GTAW process) and presenting maximum iron content of 5% at the thickness of 3 mm (the qualified thickness).
36
VIEW
ML00132 / May.2018
Seamless Pipe Overlaid with Alloy 625
M - LAS / Ni AlloyP - Seamless PipeAp - Oil and GasCd - Welding
Cm - Electrolytic Etch Micrography by SEMDf - Clad Interface
ML00095 — MIC of a Riser Control LineM - Austenitic Stainless SteelP - Fabrication WeldAp - Oil and GasCd - Brittle Behavior
Detail, by scanning electron microscopy, of the external surface of the line at the cracking position presenting branched cracks, transverse to the line axis. The surface of the fitting is fully stained (dark grey), from where the cracks start, indicating that the material loose passivation in these regions.
62
VIEW
ML00095 / Sep.2017
MIC of a Riser Control Line
M - Austenitic Stainless SteelP - Fabrication WeldAp - Oil and GasCd - Brittle Behavior
Cm - Surface Aspect by SEMDf - Branched Cracks
The aspect of the fitting surface by SEM shows multiple cracks. Interesting to observe a stained region (dark grey) that corresponds to regions where the material passivation was destroyed.
43
VIEW
ML00095 / Sep.2017
MIC of a Riser Control Line
M - Austenitic Stainless SteelP - Fabrication WeldAp - Oil and GasCd - Brittle Behavior
Cm - Surface Aspect by SEMDf - External Surface
Detail of one region that had the passivation layer destroyed .
45
VIEW
ML00095 / Sep.2017
MIC of a Riser Control Line
M - Austenitic Stainless SteelP - Fabrication WeldAp - Oil and GasCd - Brittle Behavior
Cm - Surface Aspect by SEMDf - External Surface
Detail of one region that had the passivation layer destroyed and presented corrosion cracks.
48
VIEW
ML00095 / Sep.2017
MIC of a Riser Control Line
M - Austenitic Stainless SteelP - Fabrication WeldAp - Oil and GasCd - Brittle Behavior
Cm - Surface Aspect by SEMDf - Corrosion Cracking
The aspect of the external surface of the fitting shows regions where the passivation was lost and where microcracks started already.
54
VIEW
ML00095 / Sep.2017
MIC of a Riser Control Line
M - Austenitic Stainless SteelP - Fabrication WeldAp - Oil and GasCd - Brittle Behavior
Cm - Surface Aspect by SEMDf - Microcracks
ML00075 — Hydrogen Cracking of IN 718 Subsea FastenersM - NiCrFe AlloyP - StudAp - SubseaCd - Hydrogen Embrittlement
The secondary cracks are easily observed in the fracture surface, longitudinal to the axis of the stud.
26
VIEW
ML00075 / Jun.2018
Hydrogen Cracking of IN 718 Subsea Fasteners
M - NiCrFe AlloyP - StudAp - SubseaCd - Hydrogen Embrittlement
Cm - Fractography by SEMDf - Brittle Fracture
The fracture of the stud presented both intergranular and transgranular aspects.
26
VIEW
ML00075 / Jun.2018
Hydrogen Cracking of IN 718 Subsea Fasteners
M - NiCrFe AlloyP - StudAp - SubseaCd - Hydrogen Embrittlement
Cm - Fractography by SEMDf - Brittle Fracture
The fracture of the stud presented transgranular aspects and secondary cracks that appear to be related to small broken particles.
32
VIEW
ML00075 / Jun.2018
Hydrogen Cracking of IN 718 Subsea Fasteners
M - NiCrFe AlloyP - StudAp - SubseaCd - Hydrogen Embrittlement
Cm - Fractography by SEMDf - Secondary Cracks