Ferrous Alloys

150 cases · 2183 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Ferrous Alloys — sub-branches

Carbon Steel 31Cast Iron 9High Alloy Steel 52Low Alloy Steel 56Tool Steel 2

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Microscopic detail of the cracks at the surface of the pin, close to the fracture. It is possible to see that the cracks are not associated to plastic deformation at the surface. Instead they are brittle and associated to regions where the material lost the passivation (dark grey stains at the surface). Some cracks that already opened (a little) showed deformation at the tips.
1024
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Surface Aspect by SEMDf - Multiple cracks
Aspect of the serrated walrus tool, interchangeable, that was removed at the end of its life. Dimensions of 1" thick, 2" width, 3" long.
419
VIEW
ML00084 / Mar.2020
Walrus Tool Steel
M - High Carbon Tool SteelP - ForgingAp - Mechanical IndustryCd - Removed From Service
Cm - Aspect Before AnalysisDf - General View
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
VIEW
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
Micrographic detail of the forging lap defect that appears at the nut surface like a crack, filled with oxides. The nut presented a martensitic structure in the center of the nut, but in the regions adjacent to the defect the structure is ferritic-bainitic due to decarburization. There are several globular oxides (grey spots) that became entrapped during the forging.
654
VIEW
ML00099 / Jan.2018
Forging Defect in a Cadmium Plated Nut
M - Medium Carbon SteelP - NutAp - PipingCd - Fabrication Defect
Cm - Nital Etched Micrography by OMDf - Crack
Micrography of a transverse section of the lifting part, showing interdendritic voids close to the surface at the inner diameter of the padeye. The microstructure is tempered martensite.
450
VIEW
ML00098 / Nov.2017
Brittle Fracture of a Casting Lifting Device
M - Low Alloy Medium Carbon QTP - CastingAp - LiftingCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Casting defects
Micrography of the new tube close to a region of a casting defect (shrinkage), presenting only austenitic structure with a network of primary precipitates.
351
VIEW
ML00097 / Nov.2017
Cast SS Tube Removed From High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - High Temperature
Cm - Glyceregia Etched Micrography by OMDf - Austenitic with Primary Carbides
Micrography of the external surface of the tubular equipment, close to the fracture position (it is to the top of the figure), showing multiple cracks, typical of a corrosion fatigue mechanism.
861
VIEW
ML00082 / Dec.2017
Corrosion Fatigue of a Drilling Tool
M - Low Alloy Medium Carbon QTP - Tubular ForgingAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Multiple cracks
Micrographic detail of the fatigue cracking at the margin of the flange to shell fillet weld.
484
VIEW
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

More from these cases

ML00085 — Corrosion Fatigue of a Martensitic SS PinM - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Low magnification microscopy (stereoscope) detail of the multiple cracks at the pin surface.
146
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Surface AspectDf - Multiple cracks
Aspect of the pin surface, presenting multiple cracks, paralel to the fracture position.
122
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - Multiple cracks
Aspect of the 5/8" diameter pin, that was 3" long and broke close to the center.
104
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - General View
Typical fatigue fracture, reversed bending.
74
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - Fracture
The fractographic analysis of the pin showed fatigue striation at the subcritical propagation region.
75
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Fractography by SEMDf - Fatigue Striation

+13 more from this case →

ML00084 — Walrus Tool SteelM - High Carbon Tool SteelP - ForgingAp - Mechanical IndustryCd - Removed From Service
Micrography of the tool steel, in the longitudinal section of the part. The material presented a uniform structure, tempered martensite. The tempering was in low temperature since the hardness is high (58 HRc at the surface).
87
VIEW
ML00084 / Mar.2020
Walrus Tool Steel
M - High Carbon Tool SteelP - ForgingAp - Mechanical IndustryCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Uniform Structure
Micrographic detail of the tool steel, in the longitudinal section of the part. The material presented a uniform structure, tempered martensite, with small secondary carbides. The hardness in the section is 59 HRc.
73
VIEW
ML00084 / Mar.2020
Walrus Tool Steel
M - High Carbon Tool SteelP - ForgingAp - Mechanical IndustryCd - Removed From Service
Cm - Nital Etched Micrography by OMDf - Martensite
ML00100 — Superduplex Tubing to Forging Welded JointM - Super Duplex Stainless SteelP - Fabrication WeldAp - SubseaCd - Welding
Micrography of the tubing heat affected zone.
69
VIEW
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
Micrography of the tubing heat affected zone.
68
VIEW
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
VIEW
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
Low magnification micrography of the superduplex stainless steel tubing (base metal), in the longitudinal direction. Refined ferritic-austenitic structure. The average hardness in the section is 264HV5.
58
VIEW
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
Micrography of the superduplex stainless steel tubing (base metal), in the longitudinal direction. Refined ferritic-austenitic structure.
55
VIEW
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 →

ML00099 — Forging Defect in a Cadmium Plated NutM - Medium Carbon SteelP - NutAp - PipingCd - Fabrication Defect
Micrography of the nut in a section transverse to the surface indication. There are several microcracks (parallel and perpendicular to the nut surface) filled with oxides. The nut presented a martensitic microstructure in the center of the thickness and a ferritic-bainitic microstructure at surface and adjacent to the defect, due to decarburization occurred during high temperature forging.
130
VIEW
ML00099 / Jan.2018
Forging Defect in a Cadmium Plated Nut
M - Medium Carbon SteelP - NutAp - PipingCd - Fabrication Defect
Cm - Nital Etched Micrography by OMDf - Crack
The general aspect of the 1 1/8" 2H nut, presenting rejectable indications that appear like cracks, located in the face and in the lateral side of the nut.
46
VIEW
ML00099 / Jan.2018
Forging Defect in a Cadmium Plated Nut
M - Medium Carbon SteelP - NutAp - PipingCd - Fabrication Defect
Cm - Aspect Before AnalysisDf - General View
Aspect in detail of the 1 1/8" 2H nut face, presenting rejectable indications that appear like cracks.
49
VIEW
ML00099 / Jan.2018
Forging Defect in a Cadmium Plated Nut
M - Medium Carbon SteelP - NutAp - PipingCd - Fabrication Defect
Cm - Aspect Before AnalysisDf - Lap
The general aspect of the lateral side of the 1 1/8" 2H nut, presenting a rejectable indication that looks like a straight crack.
48
VIEW
ML00099 / Jan.2018
Forging Defect in a Cadmium Plated Nut
M - Medium Carbon SteelP - NutAp - PipingCd - Fabrication Defect
Cm - Aspect Before AnalysisDf - Lap
Micrographic detail of the lap at the nut surface, as polished. The 20 microns cadmium layer is evident, penetrating in the lap.
46
VIEW
ML00099 / Jan.2018
Forging Defect in a Cadmium Plated Nut
M - Medium Carbon SteelP - NutAp - PipingCd - Fabrication Defect
Cm - As polished micrographyDf - Lap

+2 more from this case →

ML00098 — Brittle Fracture of a Casting Lifting DeviceM - Low Alloy Medium Carbon QTP - CastingAp - LiftingCd - Brittle Fracture
Aspect of the broken padeye. The outer diameter is about 10" and the thickness of the casting is about 2".
22
VIEW
ML00098 / Nov.2017
Brittle Fracture of a Casting Lifting Device
M - Low Alloy Medium Carbon QTP - CastingAp - LiftingCd - Brittle Fracture
Cm - Aspect Before AnalysisDf - General View
Aspect of the fracture surface, showing a brittle morphology. Flat fracture with chevron marks from regions close to the internal diameter of the padeye, where there are secondary cracks.
22
VIEW
ML00098 / Nov.2017
Brittle Fracture of a Casting Lifting Device
M - Low Alloy Medium Carbon QTP - CastingAp - LiftingCd - Brittle Fracture
Cm - Aspect Before AnalysisDf - Fracture
Micrography of the lifting padeye showing a dendritic path of a quenched and tempered martensitic microstructure. The segregated regions (white interdendritic regions) are more clearly identified in low magnification. Voids are located in these segregated regions.
21
VIEW
ML00098 / Nov.2017
Brittle Fracture of a Casting Lifting Device
M - Low Alloy Medium Carbon QTP - CastingAp - LiftingCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Martensite
Micrography of the lifting padeye showing a quenched and tempered martensitic microstructure. Voids are located in interdendritic segregated regions.
20
VIEW
ML00098 / Nov.2017
Brittle Fracture of a Casting Lifting Device
M - Low Alloy Medium Carbon QTP - CastingAp - LiftingCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Martensite
Micrography of the lifting padeye showing a quenched and tempered martensitic microstructure. Voids are located in interdendritic segregated regions. At this magnification the segregation is not clear.
16
VIEW
ML00098 / Nov.2017
Brittle Fracture of a Casting Lifting Device
M - Low Alloy Medium Carbon QTP - CastingAp - LiftingCd - Brittle Fracture
Cm - Nital Etched Micrography by OMDf - Martensite

+12 more from this case →

ML00097 — Cast SS Tube Removed From High Temperature ServiceM - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - High Temperature
The macrography of a transverse section of the new tube shows that there are shrinkage voids close to the internal surface, that is exposed to high temperature air. The tube is a 4" diameter and 1/4" thick.
62
VIEW
ML00097 / Nov.2017
Cast SS Tube Removed From High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - High Temperature
Cm - Transverse Section AspectDf - Casting Structure
Micrography close to the external surface of a new tube, sound.
48
VIEW
ML00097 / Nov.2017
Cast SS Tube Removed From High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - High Temperature
Cm - As polished micrographyDf - Close to the External Surface
Micrography close to the internal surface of a new tube, presenting casting defects.
47
VIEW
ML00097 / Nov.2017
Cast SS Tube Removed From High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - High Temperature
Cm - As polished micrographyDf - Close to the Internal Surface
Micrography of the tube removed from service after 6 month, close to a region of a casting defect (shrinkage), presenting austenitic structure with a network of primary precipitates (initial stage of coarsening) and intragranular secondary precipitation.
48
VIEW
ML00097 / Nov.2017
Cast SS Tube Removed From High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - High Temperature
Cm - Glyceregia Etched Micrography by OMDf - Intragranular Secondary Precipitation
The macrography of a transverse section of the tube removed from service after 6 months, with damage close to the internal tube surface. The tube is a 4" diameter and 1/4" thick.
41
VIEW
ML00097 / Nov.2017
Cast SS Tube Removed From High Temperature Service
M - Heat Resistant SteelP - Centrifugally Cast PipeAp - SiderurgyCd - High Temperature
Cm - Transverse Section AspectDf - Casting Structure

+2 more from this case →

ML00082 — Corrosion Fatigue of a Drilling ToolM - Low Alloy Medium Carbon QTP - Tubular ForgingAp - O&G Well DrillingCd - Corrosion Fatigue
Drilling tool that broke close to the region of the male connector (pin end). The fracture is at the right side of the figure.
102
VIEW
ML00082 / Dec.2017
Corrosion Fatigue of a Drilling Tool
M - Low Alloy Medium Carbon QTP - Tubular ForgingAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - Fracture
The fracture was removed from the failed part and analyzed separately. The aspect of the fracture surface is presented. It is flat, with regions of fatigue propagation and with regions of erosion by washout (to the right side of the figure).
80
VIEW
ML00082 / Dec.2017
Corrosion Fatigue of a Drilling Tool
M - Low Alloy Medium Carbon QTP - Tubular ForgingAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - Fracture
Detail of the fracture surface presenting a fatigue propagation from the outside of the tool.
69
VIEW
ML00082 / Dec.2017
Corrosion Fatigue of a Drilling Tool
M - Low Alloy Medium Carbon QTP - Tubular ForgingAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - Fatigue Fracture
Detail of the fracture surface presenting erosion by a washout, because the equipment was pressurized when the cracking became through wall.
63
VIEW
ML00082 / Dec.2017
Corrosion Fatigue of a Drilling Tool
M - Low Alloy Medium Carbon QTP - Tubular ForgingAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - Washout
Micrographic aspect of the martensitic structure at the longitudinal section.
60
VIEW
ML00082 / Dec.2017
Corrosion Fatigue of a Drilling Tool
M - Low Alloy Medium Carbon QTP - Tubular ForgingAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Nital Etched Micrography by OMDf - Martensite

+6 more from this case →

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
VIEW
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
VIEW
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
VIEW
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
The macrography of a transverse section of the shell to flange weld (Lepto's etch) shows that the cracking occurred through the shell plate thickness, at the margin of the fillet weld.
93
VIEW
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
VIEW
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 →