UNS

6 cases · 77 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Visual aspect of the internal side of the tube, after longitudinal cut, presenting the region of leakage.  The tube, that is 1.6mm thick, presented several points of localized diissolution .
457
ML00170 / Sep.2020
MIC in Aluminum Brass Tubes
M - Aluminum BrassP - Seamless tubeAp - MaritimeCd - Preferential Dissolution
Cm - Surface AspectDf - Localized Thinning
Aspect "as received" of the seamless tube at the curved position, showing the longitudinal crack and corrosion products at the tube surface.
836
ML00165 / Jul.2020
SCC of Aluminum Bronze Heating Coil
M - Aluminum BronzeP - Seamless tubeAp - Oil and GasCd - Stress Corrosion
Cm - Aspect Before AnalysisDf - General View
The scanning electron microscopy image of the internal surface of the tube in position 2 shows a localized  corrosion region with intergranular morphology, as well a crack from the corroded region.
1237
ML00086 / Nov.2017
Intergranular Corrosion of Sensitized 304SS
M - Austenitic Stainless SteelP - Seamless tubeAp - Heat ExchangerCd - Intergranular Corrosion
Cm - Surface Aspect by SEMDf - Intergranular Corrosion
Micrography of the tubing fusion line. The welding was conducted in two passes. The average hardness at the heat affected zone of the tubing is 257 HV5.
825
ML00100 / Nov.2017
Superduplex Tubing to Forging Welded Joint
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Welding
Cm - NaOH Electrolytic Etched MicroDf - Fusion Line Left Side
Image by scanning electron microscopy of the metallurgically bonded interface of the composite seamless tube (carbon steel externally claded with stainless steel), in the side of the stainless steel where a strain hardening effect plus a carbide precipitation in twins is shown.  The hardness of this region (279 HV0.3) is a lot higher than the value obtained out of this region (167 HV0.3) for the same stainless steel.
814
ML00056 / May.2018
Seamless Tube Externally Cladded with SS
M - Carbon Steel / Stainless SteelP - CladdingAp - Pulp and PaperCd - Removed From Service
Cm - Electrolytic Etch Micrography by SEMDf - Clad Interface
The micrography of the tube shows a granular structure and light deformation lines. No evidences of corrosion from the external surface (upper side of the figure) or internal surface (lower side of the figure).
440
ML00043 / Apr.2017
CuNi Condenser Tube
M - CupronickelP - Seamless tubeAp - Heat ExchangerCd - Removed From Service
Cm - FeCl3+HCl+H2O Etched MicroDf - Longitudinal Section

More from these cases

ML00170 — MIC in Aluminum Brass TubesM - Aluminum BrassP - Seamless tubeAp - MaritimeCd - Preferential Dissolution
ML00170 / Sep.2020
MIC in Aluminum Brass Tubes
M - Aluminum BrassP - Seamless tubeAp - MaritimeCd - Preferential Dissolution
Cm - Transverse Section AspectDf - Localized Thinning
ML00170 / Sep.2020
MIC in Aluminum Brass Tubes
M - Aluminum BrassP - Seamless tubeAp - MaritimeCd - Preferential Dissolution
Cm - Aspect Before AnalysisDf - Internal Surface
ML00170 / Sep.2020
MIC in Aluminum Brass Tubes
M - Aluminum BrassP - Seamless tubeAp - MaritimeCd - Preferential Dissolution
Cm - Surface AspectDf - Localized Corrosion
ML00170 / Sep.2020
MIC in Aluminum Brass Tubes
M - Aluminum BrassP - Seamless tubeAp - MaritimeCd - Preferential Dissolution
Cm - FeCl3+HCl+Ethanol Etched MicroDf - Alpha
ML00170 / Sep.2020
MIC in Aluminum Brass Tubes
M - Aluminum BrassP - Seamless tubeAp - MaritimeCd - Preferential Dissolution
Cm - FeCl3+HCl+Ethanol Etched MicroDf - Alpha

+10 more from this case →

ML00165 — SCC of Aluminum Bronze Heating CoilM - Aluminum BronzeP - Seamless tubeAp - Oil and GasCd - Stress Corrosion
Aspect of the external tube surface after cleaning. It is possible to see that the cracks are longitudinal to the tube and localized in positions where the surface is corroded.
132
ML00165 / Jul.2020
SCC of Aluminum Bronze Heating Coil
M - Aluminum BronzeP - Seamless tubeAp - Oil and GasCd - Stress Corrosion
Cm - Surface AspectDf - External Surface
Aspect of the internal tube surface after a longitudinal cut, without cleaning.  It is possible to see a clean surface inside the tube.
104
ML00165 / Jul.2020
SCC of Aluminum Bronze Heating Coil
M - Aluminum BronzeP - Seamless tubeAp - Oil and GasCd - Stress Corrosion
Cm - Surface AspectDf - Internal Surface
Micrography of the tranverse section of the tube, in the center of the thickness.  There are small grains and large grains, characterizing a dual grain size.  The large grains size is about 100 microns, more than 10 times larger than the average size of the smaller grains size.
101
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 - Dual grain sizes
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 - Alpha
ML00165 / Jul.2020
SCC of Aluminum Bronze Heating Coil
M - Aluminum BronzeP - Seamless tubeAp - Oil and GasCd - Stress Corrosion
Cm - As polished micrographyDf - Cracking

+12 more from this case →

ML00086 — Intergranular Corrosion of Sensitized 304SSM - Austenitic Stainless SteelP - Seamless tubeAp - Heat ExchangerCd - Intergranular Corrosion
Micrography of the 1.65 mm thickness tube, in the middle of the thickness of the longitudinal section.  This part of the tube is located in the colder part of the equipment, position 1.  The material presented carbide precipitation at grain boundaries (not yet fully surrounding the grains) and at this point the tube presented no internal corrosion.
338
ML00086 / Nov.2017
Intergranular Corrosion of Sensitized 304SS
M - Austenitic Stainless SteelP - Seamless tubeAp - Heat ExchangerCd - Intergranular Corrosion
Cm - Micrography by OM using A262 Method ADf - Austenite
Micrography of the 1.65 mm thickness tube, in the middle of the thickness of the longitudinal section.  This part of the tube is located in position 2, where the temperature was higher and the carbide precipitation increased during service.
272
ML00086 / Nov.2017
Intergranular Corrosion of Sensitized 304SS
M - Austenitic Stainless SteelP - Seamless tubeAp - Heat ExchangerCd - Intergranular Corrosion
Cm - Micrography by OM using A262 Method ADf - Intergranular Precipitation
Micrography of the 1.65 mm thickness tube, in the middle of the thickness of the longitudinal section.  This part of the tube is located in position 3, where intergranular and transgranular carbide precipitation occurred during service.
234
ML00086 / Nov.2017
Intergranular Corrosion of Sensitized 304SS
M - Austenitic Stainless SteelP - Seamless tubeAp - Heat ExchangerCd - Intergranular Corrosion
Cm - Micrography by OM using A262 Method ADf - Intragranular Secondary Precipitation
The low magnification image of the internal surface of the tube, in position 2, shows several points of localized corrosion, with intergranular morphology.
193
ML00086 / Nov.2017
Intergranular Corrosion of Sensitized 304SS
M - Austenitic Stainless SteelP - Seamless tubeAp - Heat ExchangerCd - Intergranular Corrosion
Cm - Surface Aspect by SEMDf - Intergranular Corrosion
Micrography of a longitudinal section of the tube in position 2, presenting thinning by intergranular corrosion at the internal surface.
193
ML00086 / Nov.2017
Intergranular Corrosion of Sensitized 304SS
M - Austenitic Stainless SteelP - Seamless tubeAp - Heat ExchangerCd - Intergranular Corrosion
Cm - Micrography by OM using A262 Method ADf - Intergranular Corrosion

+3 more from this case →

ML00100 — Superduplex Tubing to Forging Welded JointM - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Welding
ML00100 / Nov.2017
Superduplex Tubing to Forging Welded Joint
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Welding
Cm - NaOH Electrolytic Etched MicroDf - HAZ Left Side
ML00100 / Nov.2017
Superduplex Tubing to Forging Welded Joint
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Welding
Cm - NaOH Electrolytic Etched MicroDf - HAZ Left Side
Macrography of the welded joint between a forging connector (right side) and a seamless tubing (left side).  It was welded in two passes by GTAW process.
168
ML00100 / Nov.2017
Superduplex Tubing to Forging Welded Joint
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Welding
Cm - NaOH Electrolytic Etched MacroDf - Welded Joint
ML00100 / Nov.2017
Superduplex Tubing to Forging Welded Joint
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Welding
Cm - NaOH Electrolytic Etched MicroDf - Base Metal Left Side
ML00100 / Nov.2017
Superduplex Tubing to Forging Welded Joint
M - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Welding
Cm - NaOH Electrolytic Etched MicroDf - Duplex structure

+11 more from this case →

ML00056 — Seamless Tube Externally Cladded with SSM - Carbon Steel / Stainless SteelP - CladdingAp - Pulp and PaperCd - Removed From Service
The 2 1/2" nominal diameter seamless tube is externally cladded with stainless steel.
196
ML00056 / May.2018
Seamless Tube Externally Cladded with SS
M - Carbon Steel / Stainless SteelP - CladdingAp - Pulp and PaperCd - Removed From Service
Cm - Aspect Before AnalysisDf - Welded Joint
The macrography of a transverse section shows the carbon steel tube, externally cladded with stainless steel.  The tube was removed from service where it was welded to other tubes to form a wall.
156
ML00056 / May.2018
Seamless Tube Externally Cladded with SS
M - Carbon Steel / Stainless SteelP - CladdingAp - Pulp and PaperCd - Removed From Service
Cm - Kalling Etched MacroDf - Transverse Section
Macrography of the tube transversal section presenting the studied assembly.
138
ML00056 / May.2018
Seamless Tube Externally Cladded with SS
M - Carbon Steel / Stainless SteelP - CladdingAp - Pulp and PaperCd - Removed From Service
Cm - Macro Oxalic Acid Electrolytic EtchedDf - Transverse Section
Micrography of a longitudinal section of the pipe showing that the carbon steel pipe is slightly banded and there is a decarburized layer at the solid solution welded interface. The stainless steel structure (in the right side of the figure) is not revealed using the Nital etch.
126
ML00056 / May.2018
Seamless Tube Externally Cladded with SS
M - Carbon Steel / Stainless SteelP - CladdingAp - Pulp and PaperCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Longitudinal Section
Micrography of a longitudinal section of the pipe showing the carbon steel pipe , internal.
123
ML00056 / May.2018
Seamless Tube Externally Cladded with SS
M - Carbon Steel / Stainless SteelP - CladdingAp - Pulp and PaperCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Ferrite and Pearlite

+7 more from this case →

ML00043 — CuNi Condenser TubeM - CupronickelP - Seamless tubeAp - Heat ExchangerCd - Removed From Service
The material structure is monophasic.
110
ML00043 / Apr.2017
CuNi Condenser Tube
M - CupronickelP - Seamless tubeAp - Heat ExchangerCd - Removed From Service
Cm - FeCl3+HCl+H2O Etched MicroDf - Single phase
ML00043 / Apr.2017
CuNi Condenser Tube
M - CupronickelP - Seamless tubeAp - Heat ExchangerCd - Removed From Service
Cm - FeCl3+HCl+H2O solution Etched MacroDf - At the Surface
ML00043 / Apr.2017
CuNi Condenser Tube
M - CupronickelP - Seamless tubeAp - Heat ExchangerCd - Removed From Service
Cm - FeCl3+HCl+H2O Etched MicroDf - At the Surface