Damage

4 cases · 6 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Capture method: Optical Microscope Detail focus: External Surface clear all

Damage — sub-branches

Brittle Behavior 12Corrosion 39Ductile Behavior 5Fabrication Defect 20Fatigue 12High Temperature 9Hydrogen 17Lack of Sealing 1Repair Defect 1Shooting Effect 4Wear 3

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Micrography of a longitudinal section of the pipe, at the external pipe surface, where there is a corroded spot. The microstructure is tempered martensite and at the surface the pipe is slightly decarburized.
28
VIEW
ML00169 / Nov.2020
Drill Pipe Fracture in the Pipe Body
M - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - External Surface
Micrography of the external side of the bent tube, showing detachement of several grains due to intergranular corrosion. The corroded layer is about 200 microns thick at this position. The differences of colours in the corroded layer suggests a dealloying effect, also known as selective leaching.
71
VIEW
ML00165 / Jul.2020
SCC of Aluminum Bronze Heating Coil
M - Aluminum BronzeP - Seamless tubeAp - Oil and GasCd - Stress Corrosion
Cm - FeCl3+HCl+H2O Etched MicroDf - External Surface
Micrography of the external tube surface, presenting a crack at the weld margin. This cracking could have been created by thermal induced cycles (fatigue), but it did not propagate into the tube wall. In some regions of the external side of the tube the weld metal was detached.
77
VIEW
ML00163 / Jun.2020
Corrosion Fatigue of a Boiler Waterwall Tube
M - Low Carbon SteelP - Seamless tubeAp - BoilerCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - 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

More from these cases

ML00169 — Drill Pipe Fracture in the Pipe BodyM - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Corrosion Fatigue
Drill Pipe Fracture in the Pipe Body
2
VIEW
ML00169 / Nov.2020
Drill Pipe Fracture in the Pipe Body
M - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - As polished micrographyDf - External Surface
Drill Pipe Fracture in the Pipe Body
2
VIEW
ML00169 / Nov.2020
Drill Pipe Fracture in the Pipe Body
M - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - As polished micrographyDf - External Surface