Ferrous Alloys

94 cases · 225 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Capture method: Naked Eye or Stereoscope clear all

Ferrous Alloys — sub-branches

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

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Macrography of a typical corroded wire in a longitudinal section, showing loss of thickness by corrosion.
75
VIEW
ML00155 / Jan.2020
Failure of a Prestressed Concrete Steel Strand
M - High Carbon SteelP - Wire RopeAp - StructureCd - Corrosion Fatigue
Cm - NItal Etched MacroDf - Corrosion
Flat casting product presenting several thermal fatigue cracks all thorugh the surfaces. 1" thicknes.
171
VIEW
ML00001 / Dec.2017
Thermal Fatigue of Cast Iron
M - Nodular Cast IronP - CastAp - SiderurgyCd - Thermal Fatigue
Cm - Transverse Section AspectDf - Cracks Transverse to the Surface
Macrography of a longitudinal section of the crankshaft showing the rod bearing in the center (the rod is 54mm diameter), as well as two main bearings in both lateral sides. It is possible to see that the surface was heat treated and the hardened layer is about 3mm deep from the surface.
100
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - NItal Etched MacroDf - Longitudinal Section
Macrography of a section longitudinal to the pipe and transverse to the weld. The thickness of the pipe is 12,7 mm (1/2") and it was welded in 6 passes, the root pass, one fill pass and four cap passes.
855
VIEW
ML00153 / Jan.2019
X52 in a Tubular Structure
M - CMn SteelP - Seamless PipeAp - StructureCd - Qualified
Cm - NItal Etched MacroDf - Welded Joint
The longitudinal section of the shaft shows a coarse structure. Only very close to the surface the structure is slightly refined.
99
VIEW
ML00152 / Dec.2018
Low Alloy Steel Pump Shaft
M - High Strength Low AlloyP - ShaftAp - Oil and GasCd - Removed From Service
Cm - NItal Etched MacroDf - Longitudinal Section
The metallic part of the fork handle is about 9mm wide. It was cut in a transverse section and the profile is shown in this figure. The thickness is 1mm and the curvature depth is about 3mm.
86
VIEW
ML00151 / Dec.2018
Ferritic Stainless Steel of a Flatware Fork
M - Ferritic Stainless SteelP - Foodstuff ArticleAp - KitchenCd - Typical manufacturing
Cm - Transverse Section AspectDf - Formed Profile
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
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

More from these cases

ML00155 — Failure of a Prestressed Concrete Steel StrandM - High Carbon SteelP - Wire RopeAp - StructureCd - Corrosion Fatigue
Macrography of one wire that was fully cracked, in a longitudial section. The morphology shows multiple corrosion-fatigue cracking.
62
VIEW
ML00155 / Jan.2020
Failure of a Prestressed Concrete Steel Strand
M - High Carbon SteelP - Wire RopeAp - StructureCd - Corrosion Fatigue
Cm - NItal Etched MacroDf - Multiple cracks
Macrography of one wire that was overloaded, showing localized necking and large plastic deformation close to the fracture. This kind of fracture occurred for about 25% of the broken wires.
50
VIEW
ML00155 / Jan.2020
Failure of a Prestressed Concrete Steel Strand
M - High Carbon SteelP - Wire RopeAp - StructureCd - Corrosion Fatigue
Cm - NItal Etched MacroDf - Ductile Fracture
Failure of a Prestressed Concrete Steel Strand
2
VIEW
ML00155 / Jan.2020
Failure of a Prestressed Concrete Steel Strand
M - High Carbon SteelP - Wire RopeAp - StructureCd - Corrosion Fatigue
Cm - NItal Etched MacroDf - Corrosion
Failure of a Prestressed Concrete Steel Strand
3
VIEW
ML00155 / Jan.2020
Failure of a Prestressed Concrete Steel Strand
M - High Carbon SteelP - Wire RopeAp - StructureCd - Corrosion Fatigue
Cm - NItal Etched MacroDf - Longitudinal Section
ML00001 — Thermal Fatigue of Cast IronM - Nodular Cast IronP - CastAp - SiderurgyCd - Thermal Fatigue
Detail of figure 2, showing multiple fatigue cracks due to thermal cycles.
136
VIEW
ML00001 / Dec.2017
Thermal Fatigue of Cast Iron
M - Nodular Cast IronP - CastAp - SiderurgyCd - Thermal Fatigue
Cm - NItal Etched MacroDf - Cracks Transverse to the Surface
Oriundos
59
VIEW
ML00001 / Dec.2017
Thermal Fatigue of Cast Iron
M - Nodular Cast IronP - CastAp - SiderurgyCd - Thermal Fatigue
Cm - Transverse Section AspectDf - Acicular Alpha
ML00154 — High Strength Cast Iron CrankshaftM - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Macrographic detail of the hardened layer, about 3mm deep from the surface. Important to observe that the bearing is not heat treated in the radius, only in the contact area. The hardness at the surface is 430HV and the hardness in the base metal is 260HV.
100
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - NItal Etched MacroDf - Surface Layer
ML00151 — Ferritic Stainless Steel of a Flatware ForkM - Ferritic Stainless SteelP - Foodstuff ArticleAp - KitchenCd - Typical manufacturing
The fork scoop is about 53 wide and there is a transition to the handle that is 9mm wide. Exactly at that transition the fork was cut in a longitudinal section and the profile is shown in this figure. The thickness is 1mm and the curvatures of the scoop and handle are in different directions, 3mm depth concave in the handle and 10 mm depth convex in the scoop.
54
VIEW
ML00151 / Dec.2018
Ferritic Stainless Steel of a Flatware Fork
M - Ferritic Stainless SteelP - Foodstuff ArticleAp - KitchenCd - Typical manufacturing
Cm - Longitudinal Section AspectDf - Formed Profile
Aspect of the cut surface of the fork tooth in the scoop. The thickness is 1 mm and the fabrication finishing of the surface is polished. The tooth in the center was cut for analysis in the longitudinal section.
33
VIEW
ML00151 / Dec.2018
Ferritic Stainless Steel of a Flatware Fork
M - Ferritic Stainless SteelP - Foodstuff ArticleAp - KitchenCd - Typical manufacturing
Cm - Surface AspectDf - Cut Surface
ML00150 — Vibration Induced Fatigue in a SS Oil PipingM - Duplex Stainless SteelP - PipingAp - FPSOCd - Vibration Induced Fatigue
Transverse section of the 14" pipe in the center of the 2" branch using a weldolet fitting welded to the main pipe. The internal side of the pipe is to the top of the figure and the through wall fatigue cracking is located at the margem of the weld. It is possible to see that it is a full penetration weld and the fitting thickness is several times larger than the pipe thickness.
174
VIEW
ML00150 / Dec.2018
Vibration Induced Fatigue in a SS Oil Piping
M - Duplex Stainless SteelP - PipingAp - FPSOCd - Vibration Induced Fatigue
Cm - Electrolytically Etched MacroDf - Crack
Detail of the fatigue cracking, staring from the margin of the weld. The crack propagated though wall of the pipe (5 mm). The larger thickness of the weldolet requires a large amount of deposited weld metal, about 20 mm that is 4 times the pipe thickness. It is an interesting aspect to be considered by designers.
176
VIEW
ML00150 / Dec.2018
Vibration Induced Fatigue in a SS Oil Piping
M - Duplex Stainless SteelP - PipingAp - FPSOCd - Vibration Induced Fatigue
Cm - Electrolytically Etched MacroDf - Fatigue Crack
After cutting the pipe and opening the crack, the fracture appearance shows a clean fracture, flat, starting from the margem of the weld of the pipe (right side of the figure), and propagating through wall into the pipe (aproximately 5 mm thickness). The external side of the pipe is to the right side of the figure (presenting the weld finishing) and the internal side of the pipe is to the left side of the figure.
176
VIEW
ML00150 / Dec.2018
Vibration Induced Fatigue in a SS Oil Piping
M - Duplex Stainless SteelP - PipingAp - FPSOCd - Vibration Induced Fatigue
Cm - Fracture Surface AspectDf - Fracture
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
Macrography of a transverse section of the welded joint, at the fatigue crack position in the pipe. It is very interesting to observe that the crack propagated from the margin of the weld, independently of the defects in the weld (porosity and lack of fusion), and without relationship with the unbalanced structure at the cap (with a large amount of ferrite). These characteristics are detailed in the next figures.
89
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
ML00149 — Vibration Induced Fatigue in a Gas PipingM - Low Carbon SteelP - Piping spoolAp - FPSOCd - Vibration Induced Fatigue
Macrography of the 8" pipe, welded to a 2" fitting (weldolet), welded to a 2" flange. The branch line was operating in this position (horizontal line with a lateral branch) and the through thickness fatigue crack is associated to the margin of the weld in the upper part of the pipe.
50
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 - Cracking
Macrography of a section tranverse to the pipe and to the weld between the 8"pipe and the 2" fitting weldolet. The crack starts exactly at the margin of the weld, in a geometric stress concentration raiser, in a position where it growths in the pipe longitudinal direction, and propagates in a straight line, not related to any metallurgical aspect.
41
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 - Margin of the Weld Crack
Macrography of a section tranverse to the pipe and to the weld between the 8"pipe and the 2" fitting weldolet. The crack starts exactly at the margin of the weld, in a geometric stress concentration raiser, in a position where it growths in the pipe longitudinal direction, and propagates in a straight line, not related to any metallurgical aspect.
33
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 - Fatigue Crack