“fatigue”

17 cases · 98 images for “fatigue”

Crevice Corrosion in a Subsea System — Aspect Before Analysis

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Aspect before cleaning of the heavy U bolt pipe clamp, 38 mm diameter wire, at the fractured position. It is possible to see that it broke in a region where the clamp was no longer coated and there is no insert in the groove (at the internal clamp diameter). The fracture is transverse to the clamp axis.
522
VIEW
ML00171 / Feb.2021
Corrosion Fatigue of U Bolt Pipe Clamp
M - Low Carbon SteelP - BoltAp - ShipCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - General View
Aspect of a flared tubing, cold deformed at 37°, and the circumferential cracking.
483
VIEW
ML00167 / Aug.2020
Fatigue of a Flared Tubing Connection
M - Austenitic Stainless SteelP - TubingAp - EngineCd - Mechanical Fatigue
Cm - Aspect Before AnalysisDf - General View
Aspect of the waterwall during removal of the leaking tube. The leakage was detected, by visual inspection, from the outside of the boiler.
1675
VIEW
ML00163 / Jun.2020
Corrosion Fatigue of a Boiler Waterwall Tube
M - Low Carbon SteelP - Seamless tubeAp - BoilerCd - Corrosion Fatigue
Cm - Field photoDf - General View
Vertical piping in a corrosive oil producing system of a FPSO. The line is a nominal diameter 14" sch 10S (pipe thickness about 5 mm) and the flanged branch line is a 2" nominal diameter welded to the main pipe using a weldolet (forged fitting). The fatigue induced cracking occurred longitudinal to the main pipe, originated at the margem of the weld interface with the pipe.
1481
VIEW
ML00150 / Dec.2018
Vibration Induced Fatigue in a SS Oil Piping
M - Duplex Stainless SteelP - PipingAp - FPSOCd - Vibration Induced Fatigue
Cm - Aspect Before AnalysisDf - General View
Gas piping. Aspect of a branching line 2" ND with a flange, lateral to a main pipe ND 8", welded using a weldolet. The cracking is at the margin of the weld.
115
VIEW
ML00149 / Dec.2018
Vibration Induced Fatigue in a Gas Piping
M - Low Carbon SteelP - Piping spoolAp - FPSOCd - Vibration Induced Fatigue
Cm - Aspect Before AnalysisDf - General View
The four bolts have fractured in the same position, close to the end, and the corrosion marks in the thread suggest that they have been tightened only a few fillets in a tapped hole. This condition could be responsible for overloading the fillets, relaxing the applied bolt preload, and intensifying cyclic stresses.
192
VIEW
ML00130 / Jun.2018
Fatigue Fracture of Overloaded Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - O&G Well DrillingCd - Mechanical Fatigue
Cm - Aspect Before AnalysisDf - General View
Macrography of the plate (thickness 22mm, in horizontal position) to tube (thickness 12.5 mm, in vertical position) welded joint. The half V groove was welded from the top (position inside the combustion chamber) in five weld beads, and with a small fillet welded from the water side (ouside of the tube). Average hardness of the plate is 180HV1 (1kg), of the tube is 150HV1 and of the weld is 190HV1. Maximum hardness of the tube HAZ is 165HV1 and plate HAZ is 195HV1.
219
VIEW
ML00119 / Feb.2018
Thermal Fatigue of a Marine Boiler
M - Low Carbon SteelP - Fabrication WeldAp - ShipCd - Thermal Fatigue
Cm - NItal Etched MacroDf - Welded Joint
The micrography of the longitudinal section of the tube, close to OD, shows the paralel cracks, filled with oxides, perpendicular to the surface.
1444
VIEW
ML00104 / Dec.2017
Thermal Fatigue of a Boiler Tube
M - Low Carbon SteelP - Autogenously Welded TubeAp - BoilerCd - Thermal Fatigue
Cm - As polished micrographyDf - Close to the External Surface

More from these cases

ML00171 — Corrosion Fatigue of U Bolt Pipe ClampM - Low Carbon SteelP - BoltAp - ShipCd - Corrosion Fatigue
Aspect of the U bolt clamp with partial detachment of the coating (white brown) in a region where the polimeric insert (dirty white) is still in the wire groove at the internal clamp diameter (ID).
91
VIEW
ML00171 / Feb.2021
Corrosion Fatigue of U Bolt Pipe Clamp
M - Low Carbon SteelP - BoltAp - ShipCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - General View
Metallographic image of a longitudinal section of the clamp (axis in the vertical direction), showing a refined ferritic perlitic structure.
34
VIEW
ML00171 / Feb.2021
Corrosion Fatigue of U Bolt Pipe Clamp
M - Low Carbon SteelP - BoltAp - ShipCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Longitudinal Section
The clamp presented several cracks, parallel, transverse to the axis. The appearance of the cracks in the metallographic section shows that some cracks propagate and growth with a irregular path.
24
VIEW
ML00171 / Feb.2021
Corrosion Fatigue of U Bolt Pipe Clamp
M - Low Carbon SteelP - BoltAp - ShipCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Longitudinal Section
ML00167 — Fatigue of a Flared Tubing ConnectionM - Austenitic Stainless SteelP - TubingAp - EngineCd - Mechanical Fatigue
Same flared tubing, with a circumferential crack, with the focus at the internal side.
65
VIEW
ML00167 / Aug.2020
Fatigue of a Flared Tubing Connection
M - Austenitic Stainless SteelP - TubingAp - EngineCd - Mechanical Fatigue
Cm - Aspect Before AnalysisDf - General View
Micrography of a longitudinal section of the tubing showing a granular structure, austenitic.
52
VIEW
ML00167 / Aug.2020
Fatigue of a Flared Tubing Connection
M - Austenitic Stainless SteelP - TubingAp - EngineCd - Mechanical Fatigue
Cm - Oxalic Acid Electrolytic EtchDf - Longitudinal Section
Fracture surface of the tubing, close to the outer diameter.
47
VIEW
ML00167 / Aug.2020
Fatigue of a Flared Tubing Connection
M - Austenitic Stainless SteelP - TubingAp - EngineCd - Mechanical Fatigue
Cm - Fractography by SEMDf - Close to the External Surface
Micrography of a longitudinal section of the tubing where the fracture occurred. the left side is the outer diameter and the right side is the inner diameter.
37
VIEW
ML00167 / Aug.2020
Fatigue of a Flared Tubing Connection
M - Austenitic Stainless SteelP - TubingAp - EngineCd - Mechanical Fatigue
Cm - Oxalic Acid Electrolytic EtchDf - At the Surface
ML00163 — Corrosion Fatigue of a Boiler Waterwall TubeM - Low Carbon SteelP - Seamless tubeAp - BoilerCd - Corrosion Fatigue
Aspect of the tube internal surface after removal from the boiler, presenting multiple longitudinal cracks.
295
VIEW
ML00163 / Jun.2020
Corrosion Fatigue of a Boiler Waterwall Tube
M - Low Carbon SteelP - Seamless tubeAp - BoilerCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - Internal Surface
Aspect of the external surface of the leaking tube, after removal of the membrane.
262
VIEW
ML00163 / Jun.2020
Corrosion Fatigue of a Boiler Waterwall Tube
M - Low Carbon SteelP - Seamless tubeAp - BoilerCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - 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 the external tube surface, presenting the cracking at the margin of the weld. This cracking could have been created by thermal induced cycles (fatigue), but it did not propagate into the tube wall.
85
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 - Fusion Line
ML00150 — Vibration Induced Fatigue in a SS Oil PipingM - Duplex Stainless SteelP - PipingAp - FPSOCd - Vibration Induced Fatigue
Macrography of the section transverse to the ND 14" main pipe (that is only 5mm thick) and to the ND 2" branch that is a weldolet fitting welded to the main pipe and flange. This image is interesting because it shows clearly how thin is the pipe compared with the fitting thickness and the large amount of welding required to assure a full penetration weld in the weldolet.
220
VIEW
ML00150 / Dec.2018
Vibration Induced Fatigue in a SS Oil Piping
M - Duplex Stainless SteelP - PipingAp - FPSOCd - Vibration Induced Fatigue
Cm - NaOH Electrolytic Etched MacroDf - Transverse Section
Duplex stainless steel piping, in a region where the 14" ND pipe is only 5mm thick and the branch is a weldolet (forged fitting) welded to the pipe and to the flange, a lot more thicker than the pipe.
107
VIEW
ML00150 / Dec.2018
Vibration Induced Fatigue in a SS Oil Piping
M - Duplex Stainless SteelP - PipingAp - FPSOCd - Vibration Induced Fatigue
Cm - Aspect Before AnalysisDf - General View
Macrographic detail of the pipe to weldolet weld, and the through wall cracking in the pipe from the margin of the weld. The pipe thickness is only 5 mm (SCH 10S) but the large thickness of the fitting required several weld passes to create a full penetration weld.
84
VIEW
ML00150 / Dec.2018
Vibration Induced Fatigue in a SS Oil Piping
M - Duplex Stainless SteelP - PipingAp - FPSOCd - Vibration Induced Fatigue
Cm - NaOH Electrolytic Etched MacroDf - Welded Joint
Micrography of the heat affected zone of the pipe to the fitting, at the pipe position, where the weld is in angle to the pipe (welded at the pipe surface). Weld metal to the top.
85
VIEW
ML00150 / Dec.2018
Vibration Induced Fatigue in a SS Oil Piping
M - Duplex Stainless SteelP - PipingAp - FPSOCd - Vibration Induced Fatigue
Cm - NaOH Electrolytic Etched MicroDf - Heat Affected Zone
Micrography of the heat affected zone of the pipe to the fitting, at the pipe position. Base metal to the bottom of the figure and fusion line to the top.
87
VIEW
ML00150 / Dec.2018
Vibration Induced Fatigue in a SS Oil Piping
M - Duplex Stainless SteelP - PipingAp - FPSOCd - Vibration Induced Fatigue
Cm - NaOH Electrolytic Etched MicroDf - Heat Affected Zone

+9 more from this case →

ML00149 — Vibration Induced Fatigue in a Gas PipingM - Low Carbon SteelP - Piping spoolAp - FPSOCd - Vibration Induced Fatigue
Gas piping. Aspect of a branching line 2" ND, lateral to a horizontal main pipe ND 8", welded using a weldolet. In the lower part of the branch there are no cracks.
61
VIEW
ML00149 / Dec.2018
Vibration Induced Fatigue in a Gas Piping
M - Low Carbon SteelP - Piping spoolAp - FPSOCd - Vibration Induced Fatigue
Cm - Aspect Before AnalysisDf - Welded Joint
Aspect of the brach line viewed from the internal side of the main pipe, after cuting. It is possible to see that the pipe was perforated by a thermal cutting (looking the finishing aspect of the edge of the hole). The weldolet was welded only from the external side of the pipe.
62
VIEW
ML00149 / Dec.2018
Vibration Induced Fatigue in a Gas Piping
M - Low Carbon SteelP - Piping spoolAp - FPSOCd - Vibration Induced Fatigue
Cm - Aspect Before AnalysisDf - Internal Surface
Macrography of a transverse section of the 8" pipe, cut exactly in the middle of the lateral 2" branch line, showing the through thickness crack initiated at the margin of the weld, in the upper part of the pipe.
64
VIEW
ML00149 / Dec.2018
Vibration Induced Fatigue in a Gas Piping
M - Low Carbon SteelP - Piping spoolAp - FPSOCd - Vibration Induced Fatigue
Cm - NItal Etched MacroDf - Welded Joint
ML00130 — Fatigue Fracture of Overloaded BoltsM - Low Alloy Medium Carbon QTP - FastenerAp - O&G Well DrillingCd - Mechanical Fatigue
The corrosion marks in the thread surface indicate that the bolt was not properly tightened in the tapped hole. The length of thread engagement should be at least 1x of the bolt diameter, in this case 3/8".
170
VIEW
ML00130 / Jun.2018
Fatigue Fracture of Overloaded Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - O&G Well DrillingCd - Mechanical Fatigue
Cm - Aspect Before AnalysisDf - General View
The head of the bolts presented the marks that indicated they were manufactured to meet ASTM A449 type 1 bolt, that is a medium strength low alloy steel, quenched and tempered.
148
VIEW
ML00130 / Jun.2018
Fatigue Fracture of Overloaded Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - O&G Well DrillingCd - Mechanical Fatigue
Cm - Aspect Before AnalysisDf - At the Surface
Aspect of the fracture surface in low magnification, showing a flat aspect (associated to a fatigue fracture micromechanims) and a rough aspect (associated to a ductile fracture micromechanism).
167
VIEW
ML00130 / Jun.2018
Fatigue Fracture of Overloaded Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - O&G Well DrillingCd - Mechanical Fatigue
Cm - Fractography by SEMDf - General View
Micrographic aspect of the rolled thread that was heat treated later. Longitudinal section.
134
VIEW
ML00130 / Jun.2018
Fatigue Fracture of Overloaded Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - O&G Well DrillingCd - Mechanical Fatigue
Cm - Nital Etched Micrography by OMDf - At the Surface
Micrographic aspect of the rolled thread that was heat treated later. Longitudinal section. The bolt was quenched and tempered to 30HRc and presented a martensitic structure.
124
VIEW
ML00130 / Jun.2018
Fatigue Fracture of Overloaded Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - O&G Well DrillingCd - Mechanical Fatigue
Cm - Nital Etched Micrography by OMDf - At the Surface

+3 more from this case →

ML00119 — Thermal Fatigue of a Marine BoilerM - Low Carbon SteelP - Fabrication WeldAp - ShipCd - Thermal Fatigue
Micrography of the weld metal in the center os the weld. Columnar grains (of the previous austenite) with primary ferrite in the grain boundaries; ferrite with aligned second phases and acicular ferrite, intragranular.
137
VIEW
ML00119 / Feb.2018
Thermal Fatigue of a Marine Boiler
M - Low Carbon SteelP - Fabrication WeldAp - ShipCd - Thermal Fatigue
Cm - Nital Etched Micrography by OMDf - Weld Metal
Low magnification micrography of the tube HAZ, at the fusion line. The weld metal is in the right side of the figure and the tube weld metal is in the left side of the figure.
112
VIEW
ML00119 / Feb.2018
Thermal Fatigue of a Marine Boiler
M - Low Carbon SteelP - Fabrication WeldAp - ShipCd - Thermal Fatigue
Cm - Nital Etched Micrography by OMDf - Heat Affected Zone
The macrography of the surface exposed to the combustion chamber presents multiple cracks, perpendicular to the internal diamater of the tube (left side of the figure). The cracks are located in the tube and propagated into the tube wall and welded joint to the plate (right side of the figure).
79
VIEW
ML00119 / Feb.2018
Thermal Fatigue of a Marine Boiler
M - Low Carbon SteelP - Fabrication WeldAp - ShipCd - Thermal Fatigue
Cm - Surface AspectDf - At the Surface
ML00104 — Thermal Fatigue of a Boiler TubeM - Low Carbon SteelP - Autogenously Welded TubeAp - BoilerCd - Thermal Fatigue
The micrography of the longitudinal section of the tube, close to ID, shows the paralel cracks, filled with oxides, perpendicular to the surface.
229
VIEW
ML00104 / Dec.2017
Thermal Fatigue of a Boiler Tube
M - Low Carbon SteelP - Autogenously Welded TubeAp - BoilerCd - Thermal Fatigue
Cm - As polished micrographyDf - Close to the Internal Surface
The water wall tube, external diameter 60.3mm and thickness 3.9 mm, shows circunferential cracks in the middle of the section. Several other tubes have failed after 10 years in service.
716
VIEW
ML00104 / Dec.2017
Thermal Fatigue of a Boiler Tube
M - Low Carbon SteelP - Autogenously Welded TubeAp - BoilerCd - Thermal Fatigue
Cm - Aspect Before AnalysisDf - General View
Aspect of the internal surface of the tube after longitudinal cut. This position is out of the damage area and only a small amount of deposits is evident.
216
VIEW
ML00104 / Dec.2017
Thermal Fatigue of a Boiler Tube
M - Low Carbon SteelP - Autogenously Welded TubeAp - BoilerCd - Thermal Fatigue
Cm - Surface AspectDf - Internal Surface
Aspect of the internal surface of the tube after longitudinal cut. This position is at the damage area where a thick deposit is evident.
186
VIEW
ML00104 / Dec.2017
Thermal Fatigue of a Boiler Tube
M - Low Carbon SteelP - Autogenously Welded TubeAp - BoilerCd - Thermal Fatigue
Cm - Surface AspectDf - Internal Surface
Aspect of the external surface of the tube, presenting a large circunferential crack.
171
VIEW
ML00104 / Dec.2017
Thermal Fatigue of a Boiler Tube
M - Low Carbon SteelP - Autogenously Welded TubeAp - BoilerCd - Thermal Fatigue
Cm - Surface AspectDf - External Surface

+1 more from this case →