316

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Crevice Corrosion in a Subsea System — Aspect Before Analysis

Condition: Corrosion clear all

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Optical micrography of a longitudinal section of the fractured bolt, at the thread. The material is austenitic, free from carbides, and the threads were almost removed by the stress corrosion cracks.
756
VIEW
ML00157 / Feb.2020
Bolts Under Chloride SCC Conditions
M - Austenitic Stainless SteelP - BoltAp - Oil and GasCd - Stress Corrosion
Cm - Oxalic Acid Electrolytic EtchDf - Stress Corrosion Cracks
Aspect of the heat exchanger plate showing the rupture of the plate in multiple cracks, starting at the side of the crude oil with high salinity.
729
VIEW
ML00051 / Apr.2020
Chloride SCC of 316 Heat Exchanger Plate
M - Austenitic Stainless SteelP - Heat Exchanger PartAp - FPSOCd - Stress Corrosion
Cm - Aspect Before AnalysisDf - Cracking

More from these cases

ML00157 — Bolts Under Chloride SCC ConditionsM - Austenitic Stainless SteelP - BoltAp - Oil and GasCd - Stress Corrosion
Aspect of a 5/16" bolt manufactured in an AISI 316 austenitic stainless steel, that was also operating inside the pressure vessel, but was not yet damaged. It is a hexagonal head bolt, 1 1/2" long, fastened with a hexagonal nut and a lock washer.
118
VIEW
ML00157 / Feb.2020
Bolts Under Chloride SCC Conditions
M - Austenitic Stainless SteelP - BoltAp - Oil and GasCd - Stress Corrosion
Cm - Aspect Before AnalysisDf - General View
Low magnification micrography, by optical microscope, of the longitudinal section of a damaged bolt, in the center of the thickness. The microstructure is austenitic, free from carbides.
100
VIEW
ML00157 / Feb.2020
Bolts Under Chloride SCC Conditions
M - Austenitic Stainless SteelP - BoltAp - Oil and GasCd - Stress Corrosion
Cm - Oxalic Acid Electrolytic EtchDf - Austenite
Micrography, by optical microscope, of the longitudinal section of a damaged bolt, in the center of the thickness. The microstructure is austenitic, free from carbides, strain hardened. The hardness values of the material are from 200HV1 to 300HV1, that meets the class 2 of strenght (ASTM A193 B8M class 2).
79
VIEW
ML00157 / Feb.2020
Bolts Under Chloride SCC Conditions
M - Austenitic Stainless SteelP - BoltAp - Oil and GasCd - Stress Corrosion
Cm - Nital Etched Micrography by OMDf - Strain Hardened
Detail of the strain hardened austenitic microstructure. Micrography by optical microscope, of the longitudinal section of a bolt, in the center of the thickness.
76
VIEW
ML00157 / Feb.2020
Bolts Under Chloride SCC Conditions
M - Austenitic Stainless SteelP - BoltAp - Oil and GasCd - Stress Corrosion
Cm - Oxalic Acid Electrolytic EtchDf - Strain Hardened
Aspect of a broken 5/16" bolt that was operating inside the pressure vessel in a condition that exceeds the limits of use of the AISI 316 steel. The fracture is located close to the position where there was the bolt head and the threads were "removed" close to the fracture surface.
75
VIEW
ML00157 / Feb.2020
Bolts Under Chloride SCC Conditions
M - Austenitic Stainless SteelP - BoltAp - Oil and GasCd - Stress Corrosion
Cm - Aspect Before AnalysisDf - Fracture

+8 more from this case →

ML00051 — Chloride SCC of 316 Heat Exchanger PlateM - Austenitic Stainless SteelP - Heat Exchanger PartAp - FPSOCd - Stress Corrosion
Macrography of the surface of the cracked heat exchanger plate, manufactured in austenitic stainless steel.
159
VIEW
ML00051 / Apr.2020
Chloride SCC of 316 Heat Exchanger Plate
M - Austenitic Stainless SteelP - Heat Exchanger PartAp - FPSOCd - Stress Corrosion
Cm - Macro Oxalic Acid Electrolytic EtchedDf - Cracking
Micrography of the plate material presenting a granular austenitic structure, free from precipitation.
122
VIEW
ML00051 / Apr.2020
Chloride SCC of 316 Heat Exchanger Plate
M - Austenitic Stainless SteelP - Heat Exchanger PartAp - FPSOCd - Stress Corrosion
Cm - Eletrolytically Etched Micrography by OMDf - Austenite
Micrographic detail of the austenitic microstructure of the heat exchanger plate, free from carbides that suggest the adoption of a material in a solution annealed condition, although the high hardness level indicates cold working.
109
VIEW
ML00051 / Apr.2020
Chloride SCC of 316 Heat Exchanger Plate
M - Austenitic Stainless SteelP - Heat Exchanger PartAp - FPSOCd - Stress Corrosion
Cm - Eletrolytically Etched Micrography by OMDf - Austenite
Micrography presenting the transgranular morphology of the stress corrosion cracks of the austenitic plate. EDS analysis at the plate surface indicated high Cl peaks.
111
VIEW
ML00051 / Apr.2020
Chloride SCC of 316 Heat Exchanger Plate
M - Austenitic Stainless SteelP - Heat Exchanger PartAp - FPSOCd - Stress Corrosion
Cm - Eletrolytically Etched Micrography by OMDf - Corrosion Cracking
Micrographic detail of a branch transgranular crack typical of CSCC. Moreover, there is no evidence of intergranular precipitation.
99
VIEW
ML00051 / Apr.2020
Chloride SCC of 316 Heat Exchanger Plate
M - Austenitic Stainless SteelP - Heat Exchanger PartAp - FPSOCd - Stress Corrosion
Cm - Micrography by OM using A262 Method ADf - Corrosion Cracking