External Surface

3 cases · 8 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Microstructure: Duplex Ferritic Austenitic clear all

Results

SortNewestOldestTitle A-ZTitle Z-A
Macroscopic aspect of the outer diameter of the flanged sleeve presenting adhered products at the surface. The flanged sleeve was manufactured by centrifugal casting in a lean duplex stainless steel and it was externally coated by thermal spray (TS) in a position of sealing. After 5 years in service the system suffered leakage.
569
VIEW
ML00147 / Aug.2018
WC Layer Detached from a Cast Lean Duplex
M - Lean Duplex Stainless SteelP - Centrifugal CastingAp - ShipCd - Lack of Sealing
Cm - Aspect Before AnalysisDf - External Surface
Image of the external surface of the valve body at the region where the Alloy 625 insert was fillet weld to the SDSS valve body. The surface was later machined, so it is possible to see only a mark indicating where the weld is. The brittle crack is arrested at the margin of the weld. It is possible to see strong deformation at the crack tip when it arrives the weld.
41
VIEW
ML00134 / Aug.2020
Brittle Fracture of a Superduplex Valve Body
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Fracture
Cm - Aspect Before AnalysisDf - External Surface
Detail of the longitudinal through wall cracking in the fitting welded to a tubing, ND 5/8" in a hydraulic line.
87
VIEW
ML00094 / Sep.2017
MIC of a Subsea Hydraulic Line
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Behavior
Cm - Aspect Before AnalysisDf - External Surface

More from these cases

ML00147 — WC Layer Detached from a Cast Lean DuplexM - Lean Duplex Stainless SteelP - Centrifugal CastingAp - ShipCd - Lack of Sealing
Detail of the external surface of the sleeve where the surface coating was detached, creating a lack of sealing condition.
67
VIEW
ML00147 / Aug.2018
WC Layer Detached from a Cast Lean Duplex
M - Lean Duplex Stainless SteelP - Centrifugal CastingAp - ShipCd - Lack of Sealing
Cm - Surface AspectDf - External Surface
Micrography of a longitudinal section of the sleeve, at the external surface where there are two layers of coating. The electrolytic etch evidenced the duplex stainless steel substrate (bottom of the figure) and the weave interface of the substrate and the first thermal spray layer, about 1 mm thick, in a stainless steel. The surface layer, of tugnsten carbide, about 0.2 mm thick, is black and not clearly visible in this figure.
50
VIEW
ML00147 / Aug.2018
WC Layer Detached from a Cast Lean Duplex
M - Lean Duplex Stainless SteelP - Centrifugal CastingAp - ShipCd - Lack of Sealing
Cm - NaOH Electrolytic Etched MicroDf - External Surface
General view of the 10" diameter flanged sleeve, with the sealing rings of the seal box assembled at the sleeve external surface. The right side of the figure shows the surface region where the a lack of seal was identified, with adhered products.
25
VIEW
ML00147 / Aug.2018
WC Layer Detached from a Cast Lean Duplex
M - Lean Duplex Stainless SteelP - Centrifugal CastingAp - ShipCd - Lack of Sealing
Cm - Aspect Before AnalysisDf - External Surface
ML00094 — MIC of a Subsea Hydraulic LineM - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Behavior
Aspect by scanning electron microscopy of the cracking at the external surface of the fitting.
47
VIEW
ML00094 / Sep.2017
MIC of a Subsea Hydraulic Line
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Behavior
Cm - Surface Aspect by SEMDf - External Surface
Aspect by scanning electron microscopy of the cracking at the external surface of the fitting. Interesting to observe that the cracks are deformed.
39
VIEW
ML00094 / Sep.2017
MIC of a Subsea Hydraulic Line
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Brittle Behavior
Cm - Surface Aspect by SEMDf - External Surface