Sampling and Analysis

4 cases · 15 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Standard: Modified clear all

Sampling and Analysis — sub-branches

Base Metal 1Broken Testpiece 4Fusion Line 1General View 5Longitudinal Section 2Microhardness identations 2

Results

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Aged microstructure of the HP stainless steel, modified with 1%Nb, cast fitting, tubular, operating for 6 years in a furnace which design temperature is 1100°C. The material presented a network of primary carbides, white and grey, and an austenitic matrix with coalescing secondary precipitation. Some voids. The Vickers identation indicates a hardness value about 260HV 100g in the aged austenitic matrix.
491
VIEW
ML00173 / May.2021
Welding Cracks in an Aged HP Cast Fitting
M - Heat Resistant SteelP - Cast FtittingAp - PetrochemicalCd - Welding
Cm - Kalling Etched Micrography by OMDf - Microhardness identations
General view of the broken socket. The failure occurred during service, when the tool was tightening 3 3/4" bolts at 75% of the torque capacity. The fracture occurred associated to the smaller section of the socket, thickness of 13 mm, at the corner of the radio, that is a stress concentration raiser.
602
VIEW
ML00161 / Mar.2020
Brittle Fracture of a High Strength Socket
M - Medium Carbon Tool SteelP - ToolAp - Oil and GasCd - Brittle Fracture
Cm - Aspect Before AnalysisDf - General View
Lateral image of a collapsed API 5D grade S135 drill pipe, presenting the fractured region (bottom of the figure) at the pipe body. Although the pipe steel is of a high strenght, the fracture characteristic is ductile, evidencing strong plastic deformation.
545
VIEW
ML00159 / Mar.2020
Collapse of a Drill Pipe
M - Low Alloy Medium Carbon QTP - Drill PipeAp - O&G Well DrillingCd - Ductile Behavior
Cm - Aspect Before AnalysisDf - General View
The micrography in the longitudinal section in the middle of the thickness shows a light banding. Quenched and tempered structure.
346
VIEW
ML00037 / Jun.2017
LAS Forging for Pump Body
M - Low Alloy Medium Carbon QTP - Heat Treated PartAp - O&G Well DrillingCd - Typical manufacturing
Cm - Nital Etched Micrography by OMDf - Longitudinal Section

More from these cases

ML00173 — Welding Cracks in an Aged HP Cast FittingM - Heat Resistant SteelP - Cast FtittingAp - PetrochemicalCd - Welding
Condition of the joint between the centrifugally cast tube (bottom) and the buttered fitting (top). During this welding the cast fitting (buttered) showed several cracks but after removal of the fitting it was clear that the cracks were formed during the buttering and not during the joining.
46
VIEW
ML00173 / May.2021
Welding Cracks in an Aged HP Cast Fitting
M - Heat Resistant SteelP - Cast FtittingAp - PetrochemicalCd - Welding
Cm - Aspect Before AnalysisDf - General View
Cast fitting microstructure. Network of primary carbides and austenitic matrix with coalescing secondary precipitation.
37
VIEW
ML00173 / May.2021
Welding Cracks in an Aged HP Cast Fitting
M - Heat Resistant SteelP - Cast FtittingAp - PetrochemicalCd - Welding
Cm - Kalling Etched Micrography by OMDf - Base Metal
Aspect of the broken tensile testpiece, cylindrical, in a longitudinal direction in the tubular casting, showing zero elongation and zero area reduction. The Yield Strenght (348MPa) is very close to the Ultimate Strenght (352MPa) in the tensile test. Yield to Ultimate ratio of 0.98.
27
VIEW
ML00173 / May.2021
Welding Cracks in an Aged HP Cast Fitting
M - Heat Resistant SteelP - Cast FtittingAp - PetrochemicalCd - Welding
Cm - Testpiece aspectDf - Broken Testpiece
This macrography shows a longitudinal section of the tubular cast fitting. The external side is to the top and the internal side to the bottom. The buttering layer is evident in the groove that would be welded to the centrifugall cast tube (right side) and part of the ID and OD. During the buttering welding of the casting the cracks were not detected because they were formed in the center of the thickness and some have propagated to the internal diameter, but not to the external diameter. They opened only when the buttered casting was welded to the tube.
20
VIEW
ML00173 / May.2021
Welding Cracks in an Aged HP Cast Fitting
M - Heat Resistant SteelP - Cast FtittingAp - PetrochemicalCd - Welding
Cm - Kalling Etched MacroDf - Longitudinal Section
As polished micrography of the fusion line presenting several microcracks . The base metal is to the top and the weld metal is to the bottom.
23
VIEW
ML00173 / May.2021
Welding Cracks in an Aged HP Cast Fitting
M - Heat Resistant SteelP - Cast FtittingAp - PetrochemicalCd - Welding
Cm - As polished micrographyDf - Fusion Line

+2 more from this case →

ML00161 — Brittle Fracture of a High Strength SocketM - Medium Carbon Tool SteelP - ToolAp - Oil and GasCd - Brittle Fracture
General view of the broken socket. It was broken in two parts and shows no evidences of plastic deformation associated to the rupture.
93
VIEW
ML00161 / Mar.2020
Brittle Fracture of a High Strength Socket
M - Medium Carbon Tool SteelP - ToolAp - Oil and GasCd - Brittle Fracture
Cm - Aspect Before AnalysisDf - General View
General view of the broken socket, showing no plastic deformation asociated to the rupture. Looking from this side it is possible to see that the fracture followed the interface of the stem with the socket head.
80
VIEW
ML00161 / Mar.2020
Brittle Fracture of a High Strength Socket
M - Medium Carbon Tool SteelP - ToolAp - Oil and GasCd - Brittle Fracture
Cm - Aspect Before AnalysisDf - General View
Fractography of the broken Charpy V testpiece, in a high strength steel that absorbed 11 Joules at 20°C. Quasicleavage and dimples are the main fracture micromechanisms with some secondary cracks that appear to be intergranular, exactly as the fracture of the part.
48
VIEW
ML00161 / Mar.2020
Brittle Fracture of a High Strength Socket
M - Medium Carbon Tool SteelP - ToolAp - Oil and GasCd - Brittle Fracture
Cm - Fractography by SEMDf - Broken Testpiece
Fractography of the broken tensile testpiece, in a high strength steel (about 260Ksi Yield Strength) that presented 10% elongation. The fracture micromechanism in a static test is quasicleavage and dimples, with some secondary cracks that appear to be intergranular, exactly as the fracture of the part.
53
VIEW
ML00161 / Mar.2020
Brittle Fracture of a High Strength Socket
M - Medium Carbon Tool SteelP - ToolAp - Oil and GasCd - Brittle Fracture
Cm - Fractography by SEMDf - Broken Testpiece