Pressure Vessel

5 cases · 43 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Micrographic detail of the fatigue cracking at the margin of the flange to shell fillet weld.
484
ML00050 / Nov.2017
Fatigue Failure of a 316SS Pressure Stabilizer
M - Austenitic Stainless SteelP - Fabrication WeldAp - Chemical IndustryCd - Mechanical Fatigue
Cm - Micrography by OM using A262 Method ADf - Fatigue Crack
The macrography of a longitudinal section of the shell plate (sample removed from the boiler), at the position of the fillet weld (sealing weld) with a tube, where surface welding repairs created conditions for cracking the base material in a transgranular morphology. Several cracks were identify starting from the steam drum internal surface.
448
ML00019 / Apr.2017
Transgranular SCC in Boiler Steam Drum
M - CMn SteelP - Rolled PlateAp - BoilerCd - Stress Corrosion
Cm - Transverse Section AspectDf - Cracks
Typical branched stress corrosion cracks in a low carbon steel, ferritic-pertlitic structure. The cracks are filled with corrosion products.
771
ML00018 / Apr.2017
SCC in Boiler Steam Drum
M - Low Carbon SteelP - Rolled PlateAp - BoilerCd - Stress Corrosion
Cm - Nital Etched Micrography by OMDf - Branched Cracks
Steam drum presenting cracks in the shell, connecting tube holes.
1704
ML00020 / Apr.2017
Intergranular SCC in Boiler Steam Drum Repair
M - Low Carbon SteelP - Repair WeldAp - BoilerCd - Stress Corrosion
Cm - Aspect Before AnalysisDf - Cracking
The internal surface of the 2 1/2" thickness plate drum was welded to attach a baffle plate (1/4" thick) using two fillets (one in each side of the plate to shell), but the welding procedure was not suitable since cracks appeared underbead, although they were detected only after 6 month in operation, when the baffle was removed. The picture shows a macrography of the surface, with the cracking.
698
ML00008 / Nov.2017
Cold Cracks in CMn Steel Pressure Vessel
M - CMn SteelP - In Field WeldAp - BoilerCd - Welding Defect
Cm - NItal Etched MacroDf - Cracking

More from these cases

ML00050 — Fatigue Failure of a 316SS Pressure StabilizerM - Austenitic Stainless SteelP - Fabrication WeldAp - Chemical IndustryCd - Mechanical Fatigue
Aspect of the equipment presenting a through wall cracking at the margin of the fillet weld.
142
ML00050 / Nov.2017
Fatigue Failure of a 316SS Pressure Stabilizer
M - Austenitic Stainless SteelP - Fabrication WeldAp - Chemical IndustryCd - Mechanical Fatigue
Cm - Aspect Before AnalysisDf - Cracking
Macrography of the welded joint between the flange and the shell, indicating the position where the cracking   was detected, at 90°.
116
ML00050 / Nov.2017
Fatigue Failure of a 316SS Pressure Stabilizer
M - Austenitic Stainless SteelP - Fabrication WeldAp - Chemical IndustryCd - Mechanical Fatigue
Cm - Macro Oxalic Acid Electrolytic EtchedDf - Welded Joint
The shell plate micrography showed an austenitic structure.
101
ML00050 / Nov.2017
Fatigue Failure of a 316SS Pressure Stabilizer
M - Austenitic Stainless SteelP - Fabrication WeldAp - Chemical IndustryCd - Mechanical Fatigue
Cm - Micrography by OM using A262 Method ADf - Austenite
ML00050 / Nov.2017
Fatigue Failure of a 316SS Pressure Stabilizer
M - Austenitic Stainless SteelP - Fabrication WeldAp - Chemical IndustryCd - Mechanical Fatigue
Cm - Transverse Section AspectDf - Cracking
Fracture surface after opening the shell cracking, presenting fatigue striation.  The fracture presents also foreign particles.
132
ML00050 / Nov.2017
Fatigue Failure of a 316SS Pressure Stabilizer
M - Austenitic Stainless SteelP - Fabrication WeldAp - Chemical IndustryCd - Mechanical Fatigue
Cm - Fractography by SEMDf - Fatigue Striation

+3 more from this case →

ML00019 — Transgranular SCC in Boiler Steam DrumM - CMn SteelP - Rolled PlateAp - BoilerCd - Stress Corrosion
Schematic drawing presenting the longitudinal section of the shell plate (sample removed from the boiler), at the position of the fillet weld (sealing weld) with a tube,  where surface welding repairs created conditions for cracking the base material in a transgranular morphology. Several cracks were identify starting from the steam drum internal surface.
120
ML00019 / Apr.2017
Transgranular SCC in Boiler Steam Drum
M - CMn SteelP - Rolled PlateAp - BoilerCd - Stress Corrosion
Cm - Identification drawingDf - Cracks
Micrography of a transverse section of the shell plate in a cracked position showing the transgranular morphology of the stress corrosion cracks.
167
ML00019 / Apr.2017
Transgranular SCC in Boiler Steam Drum
M - CMn SteelP - Rolled PlateAp - BoilerCd - Stress Corrosion
Cm - Nital Etched Micrography by SEMDf - Transgranular Cracking
ML00019 / Apr.2017
Transgranular SCC in Boiler Steam Drum
M - CMn SteelP - Rolled PlateAp - BoilerCd - Stress Corrosion
Cm - Nital Etched Micrography by OMDf - Ferrite and Pearlite
ML00019 / Apr.2017
Transgranular SCC in Boiler Steam Drum
M - CMn SteelP - Rolled PlateAp - BoilerCd - Stress Corrosion
Cm - Nital Etched Micrography by OMDf - Ferrite and Pearlite
ML00019 / Apr.2017
Transgranular SCC in Boiler Steam Drum
M - CMn SteelP - Rolled PlateAp - BoilerCd - Stress Corrosion
Cm - Nital Etched Micrography by OMDf - Branched Cracks

+4 more from this case →

ML00018 — SCC in Boiler Steam DrumM - Low Carbon SteelP - Rolled PlateAp - BoilerCd - Stress Corrosion
Ferritic perlitic structure of the shell plate.
207
ML00018 / Apr.2017
SCC in Boiler Steam Drum
M - Low Carbon SteelP - Rolled PlateAp - BoilerCd - Stress Corrosion
Cm - Nital Etched Micrography by OMDf - Ferrite and Pearlite
Macrography of a transverse section of the steam drum sample that was removed after the inspection had detected multiple cracks propagating into the thickness, more than 50% deep in the thickness.
190
ML00018 / Apr.2017
SCC in Boiler Steam Drum
M - Low Carbon SteelP - Rolled PlateAp - BoilerCd - Stress Corrosion
Cm - NItal Etched MacroDf - Transverse Section
Micrography of the crack at the internal surface of the steam drum.  The shell plate presents a ferritic perlitic structure.
162
ML00018 / Apr.2017
SCC in Boiler Steam Drum
M - Low Carbon SteelP - Rolled PlateAp - BoilerCd - Stress Corrosion
Cm - Nital Etched Micrography by OMDf - Branched Cracks
Micrography of a crack, in a sample as polished, presenting the opened crack.
144
ML00018 / Apr.2017
SCC in Boiler Steam Drum
M - Low Carbon SteelP - Rolled PlateAp - BoilerCd - Stress Corrosion
Cm - Micrography by OMDf - Branched Cracks
Stress corrosion cracks propagating in the ferritic-perlitic structure.
120
ML00018 / Apr.2017
SCC in Boiler Steam Drum
M - Low Carbon SteelP - Rolled PlateAp - BoilerCd - Stress Corrosion
Cm - Nital Etched Micrography by OMDf - Branched Cracks

+3 more from this case →

ML00020 — Intergranular SCC in Boiler Steam Drum RepairM - Low Carbon SteelP - Repair WeldAp - BoilerCd - Stress Corrosion
Aspect of the drum shell after removing the tubes and macroetching, indicating that the cracks were located in repair welded regions.
342
ML00020 / Apr.2017
Intergranular SCC in Boiler Steam Drum Repair
M - Low Carbon SteelP - Repair WeldAp - BoilerCd - Stress Corrosion
Cm - Aspect by NDTDf - Cracks
A small sample was removed from the steam drum and the micrography shows that the cracks are intergranular (previous austenite) and located in the weld metal.
285
ML00020 / Apr.2017
Intergranular SCC in Boiler Steam Drum Repair
M - Low Carbon SteelP - Repair WeldAp - BoilerCd - Stress Corrosion
Cm - Nital Etched Micrography by OMDf - Corrosion Cracking
The micrography of the small sample removed from the steam drum shows that the cracks are intergranular (previous austenite) and located in the weld metal.
274
ML00020 / Apr.2017
Intergranular SCC in Boiler Steam Drum Repair
M - Low Carbon SteelP - Repair WeldAp - BoilerCd - Stress Corrosion
Cm - Nital Etched Micrography by OMDf - Corrosion Cracking
Secondary cracks in the weld metal showing an intergranular morphology. Stress Corrosion Cracking.
249
ML00020 / Apr.2017
Intergranular SCC in Boiler Steam Drum Repair
M - Low Carbon SteelP - Repair WeldAp - BoilerCd - Stress Corrosion
Cm - Nital Etched Micrography by OMDf - Corrosion Cracking
Detail of the secondary cracks in the weld metal with intergranular morphology. Stress Corrosion Cracking.
251
ML00020 / Apr.2017
Intergranular SCC in Boiler Steam Drum Repair
M - Low Carbon SteelP - Repair WeldAp - BoilerCd - Stress Corrosion
Cm - Nital Etched Micrography by OMDf - Corrosion Cracking

+1 more from this case →

ML00008 — Cold Cracks in CMn Steel Pressure VesselM - CMn SteelP - In Field WeldAp - BoilerCd - Welding Defect
Micrography of a longitudinal section of the shell plate base metal, presenting a typical ferritic-perlitic microstructure.
149
ML00008 / Nov.2017
Cold Cracks in CMn Steel Pressure Vessel
M - CMn SteelP - In Field WeldAp - BoilerCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Ferrite and Pearlite
Higher magnification of the ferritic-perlitic microstructure of the shell plate in the longitudinal section.
129
ML00008 / Nov.2017
Cold Cracks in CMn Steel Pressure Vessel
M - CMn SteelP - In Field WeldAp - BoilerCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Ferrite and Pearlite
Cold cracking of the fillet weld adopted to attach a flat support into a vessel shell in the internal side, using an unsuitable welding procedure that created a too high hardness HAZ.
123
ML00008 / Nov.2017
Cold Cracks in CMn Steel Pressure Vessel
M - CMn SteelP - In Field WeldAp - BoilerCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Cracks
Cold cracking of the fillet weld adopted to attach a flat support into a vessel shell in the internal side, using an unsuitable welding procedure that created a too high hardness HAZ. The cracks are mainly located at the fusion line.
118
ML00008 / Nov.2017
Cold Cracks in CMn Steel Pressure Vessel
M - CMn SteelP - In Field WeldAp - BoilerCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Cracks
Cold cracking of the fillet weld adopted to attach a flat support into a vessel shell in the internal side, using an unsuitable welding procedure that created a too high hardness HAZ. Several internal cracks at the fusion line.
101
ML00008 / Nov.2017
Cold Cracks in CMn Steel Pressure Vessel
M - CMn SteelP - In Field WeldAp - BoilerCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Cracks

+2 more from this case →