Sampling and Analysis

4 cases · 23 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Microstructure: Martensite and Retained Austenite clear all

Sampling and Analysis — sub-branches

At the Surface 3Base Metal 2General View 3Heat Affected Zone 2In the Center of the Thickness 1Longitudinal Section 2Transverse Section 1Weld Metal 5Weld Repair 4

Results

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The valve body cylindrical diameter is 6 5/8" and the actuator hole in the body is about 2" diameter. The crack is associated to the hole edge, propagating transverse to the body.
71
VIEW
ML00162 / Apr.2020
Valve Body Crack Growth from Weld Defects
M - Low Alloy Medium Carbon QTP - Valve BodyAp - O&G Well DrillingCd - Fatigue Induced by a Defect
Cm - Aspect Before AnalysisDf - General View
General view of the nodular cast iron crankshaft, 240 mm long, in process of heat treatment. The main and rod bearings, 54 mm diameter, are heat treated by localized quenching and tempering.
1018
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Aspect Before AnalysisDf - General View
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
Tempered martensitic structure of the plate base metal.
93
VIEW
ML00010 / Oct.2017
Cold Cracks in a Gouged Weld Metal
M - Low Alloy Low Carbon QTP - Rolled PlateAp - OffshoreCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Base Metal

More from these cases

ML00162 — Valve Body Crack Growth from Weld DefectsM - Low Alloy Medium Carbon QTP - Valve BodyAp - O&G Well DrillingCd - Fatigue Induced by a Defect
The figure illustrates the position of the ball and seats, as well as the valve actuator. The crack is located at the edge of the actuator hole, transverse to the cylindrical body.
63
VIEW
ML00162 / Apr.2020
Valve Body Crack Growth from Weld Defects
M - Low Alloy Medium Carbon QTP - Valve BodyAp - O&G Well DrillingCd - Fatigue Induced by a Defect
Cm - Aspect Before AnalysisDf - Longitudinal Section
Macrography of the longitudinal section of the valve body, at the cracked position close to the actuator hole. The valve body is 40 mm thick and at this position it is possible to see that there are two regions where the body was welded, close to the inner surface (bottom) and at the close to the outer surface (top). The through wall crack presented a branch aspect close to the repair in the ID and a straight aspect when propagating from the repair.
55
VIEW
ML00162 / Apr.2020
Valve Body Crack Growth from Weld Defects
M - Low Alloy Medium Carbon QTP - Valve BodyAp - O&G Well DrillingCd - Fatigue Induced by a Defect
Cm - NItal Etched MacroDf - Weld Repair
Low magnification micrography at the weld repair close to the internal surface of the valve body, in a longitudinal section. Weld metal to the bottom and heat affected zone to the top.
42
VIEW
ML00162 / Apr.2020
Valve Body Crack Growth from Weld Defects
M - Low Alloy Medium Carbon QTP - Valve BodyAp - O&G Well DrillingCd - Fatigue Induced by a Defect
Cm - Nital Etched Micrography by OMDf - Weld Repair
Low magnification micrography at the weld repair close to the internal surface of the valve body, in a longitudinal section. Weld metal to the right and heat affected zone to the left.
30
VIEW
ML00162 / Apr.2020
Valve Body Crack Growth from Weld Defects
M - Low Alloy Medium Carbon QTP - Valve BodyAp - O&G Well DrillingCd - Fatigue Induced by a Defect
Cm - Nital Etched Micrography by OMDf - Weld Repair
Micrography of the weld repair at the fusion line. At this magnification it is possible to identify several voids at interdendritic positions.
26
VIEW
ML00162 / Apr.2020
Valve Body Crack Growth from Weld Defects
M - Low Alloy Medium Carbon QTP - Valve BodyAp - O&G Well DrillingCd - Fatigue Induced by a Defect
Cm - Nital Etched Micrography by OMDf - Weld Repair

+3 more from this case →

ML00154 — High Strength Cast Iron CrankshaftM - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Micrography of a crankshaft longitudinal section at the shaft edge, in the as polished condition, presenting nodular graphite, well distruibuted.
139
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - As polished micrographyDf - At 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
Micrography of the crankshaft at the surface, in the radio that is not heat treated. The microstructure is nodules of graphite in a ferritic and pearlitic matrix, predominantly pearlitic.
96
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by OMDf - At the Surface
Micrography of the shaft at the surface, in a heat treated position. Graphite in nodules. Dark blue martensitic microstructure around the nodules and white islands of martensitic with retained austenite microstructure (not clearly identified at this low magnification).
68
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by OMDf - At the Surface
Micrography of the crankshaft in the center of the thickness. The microstructure is nodules of graphite in a ferritic and pearlitic matrix, predominantly pearlitic.
35
VIEW
ML00154 / Jan.2019
High Strength Cast Iron Crankshaft
M - Nodular Cast IronP - CastingAp - EngineCd - Surface treatment
Cm - Nital Etched Micrography by OMDf - In the Center of the Thickness
ML00010 — Cold Cracks in a Gouged Weld MetalM - Low Alloy Low Carbon QTP - Rolled PlateAp - OffshoreCd - Welding Defect
Detail of the tempered martensitic structure of the plate base metal. Hardness level of 27 HRc.
92
VIEW
ML00010 / Oct.2017
Cold Cracks in a Gouged Weld Metal
M - Low Alloy Low Carbon QTP - Rolled PlateAp - OffshoreCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Base Metal
Low magnification micrography of a transverse section of the weld at the heat affected zone region. The macrosection was hardness tested and the base metal hardness is 27HRc, the HAZ is 32HRc and the weld metal is 45HRc, revealing something wrong in the weld metal at the position close to the cracked area.
79
VIEW
ML00010 / Oct.2017
Cold Cracks in a Gouged Weld Metal
M - Low Alloy Low Carbon QTP - Rolled PlateAp - OffshoreCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Transverse Section
High temperature heat affected zone of the plate, welded in repair. The micrography was taken from a sample collected close to the cracked region, but not containing any macroscopic cracking.
76
VIEW
ML00010 / Oct.2017
Cold Cracks in a Gouged Weld Metal
M - Low Alloy Low Carbon QTP - Rolled PlateAp - OffshoreCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Heat Affected Zone
Detail of the high temperature heat affected zone of the plate, welded in repair.
69
VIEW
ML00010 / Oct.2017
Cold Cracks in a Gouged Weld Metal
M - Low Alloy Low Carbon QTP - Rolled PlateAp - OffshoreCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Heat Affected Zone
The weld metal, hard, presented a martensitic structure, probably due to the localized increase in carbon content, from the unsuitable carbon arc gouging procedure.
63
VIEW
ML00010 / Oct.2017
Cold Cracks in a Gouged Weld Metal
M - Low Alloy Low Carbon QTP - Rolled PlateAp - OffshoreCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Weld Metal

+1 more from this case →