Damage

3 cases · 23 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Product: Bolt Standard: A Capture method: Optical Microscope clear all

Damage — sub-branches

Corrosion 1Fatigue 1High Temperature 1

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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
Micrographic aspect of the rolled thread that was heat treated later. Longitudinal section.
134
VIEW
ML00130 / Jun.2018
Fatigue Fracture of Overloaded Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - O&G Well DrillingCd - Mechanical Fatigue
Cm - Nital Etched Micrography by OMDf - At the Surface
Micrography of a longitudinal section of the bolt at the fracture surface. The material showed several creep voids and interconnected cracks. The broken bolt remained in service during some time and the fracture surface presented a thick oxide layer(grey). As polished.
529
VIEW
ML00004 / Jun.2018
Creep in High Temperature Bolts
M - CrMo SteelP - FastenerAp - Gas TurbineCd - Creep
Cm - Micrography by OMDf - Oxide Layer

More from these cases

ML00157 — Bolts Under Chloride SCC ConditionsM - Austenitic Stainless SteelP - BoltAp - Oil and GasCd - Stress Corrosion
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
Optical micrography of a longitudinal section of the fractured bolt, at the thread. The material is austenitic, free from carbides, and the threads were fully cracked by the stress corrosion mechanism.
58
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
Optical micrography of a longitudinal section of the fractured bolt, under the thread, showing stress corrosion cracks through the section.
46
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

+2 more from this case →

ML00130 — Fatigue Fracture of Overloaded BoltsM - Low Alloy Medium Carbon QTP - FastenerAp - O&G Well DrillingCd - Mechanical Fatigue
Micrographic aspect of the rolled thread that was heat treated later. Longitudinal section. The bolt was quenched and tempered to 30HRc and presented a martensitic structure.
124
VIEW
ML00130 / Jun.2018
Fatigue Fracture of Overloaded Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - O&G Well DrillingCd - Mechanical Fatigue
Cm - Nital Etched Micrography by OMDf - At the Surface
Micrographic detail of the rolled thread that was heat treated later. The bolt was quenched and tempered to 30 HRc and presented a martensitic structure.
111
VIEW
ML00130 / Jun.2018
Fatigue Fracture of Overloaded Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - O&G Well DrillingCd - Mechanical Fatigue
Cm - Nital Etched Micrography by OMDf - Martensite
The microstructure of the bolt is martensitic in the center of the thickness. Longitudinal section.
110
VIEW
ML00130 / Jun.2018
Fatigue Fracture of Overloaded Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - O&G Well DrillingCd - Mechanical Fatigue
Cm - Nital Etched Micrography by OMDf - In the Center of the Thickness
The microstructure of the bolt is martensitic in the center of the thickness. Longitudinal section.
103
VIEW
ML00130 / Jun.2018
Fatigue Fracture of Overloaded Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - O&G Well DrillingCd - Mechanical Fatigue
Cm - Nital Etched Micrography by OMDf - Martensite
Micrographic aspect of the rolled thread that was heat treated later. Longitudinal section.
115
VIEW
ML00130 / Jun.2018
Fatigue Fracture of Overloaded Bolts
M - Low Alloy Medium Carbon QTP - FastenerAp - O&G Well DrillingCd - Mechanical Fatigue
Cm - Nital Etched Micrography by OMDf - At the Surface

+3 more from this case →

ML00004 — Creep in High Temperature BoltsM - CrMo SteelP - FastenerAp - Gas TurbineCd - Creep
Micrographic detail of the creep voids and interconnected cracks. The broken bolt remained in service during some time and the fracture surface presented a thick oxide layer(grey). As polished.
121
VIEW
ML00004 / Jun.2018
Creep in High Temperature Bolts
M - CrMo SteelP - FastenerAp - Gas TurbineCd - Creep
Cm - Micrography by OMDf - Interconnected Cracks
Micrographic detail of the creep voids and interconnected cracks. The broken bolt remained in service during some time and the fracture surface presented a thick oxide layer(grey). As polished.
101
VIEW
ML00004 / Jun.2018
Creep in High Temperature Bolts
M - CrMo SteelP - FastenerAp - Gas TurbineCd - Creep
Cm - Micrography by OMDf - Voids
Micrography of a longitudinal section of a CrMov steel bolt that broke in service by a creep mechanism in a gas turbine. Tempered structure. Interconnected cracks paralled to the fracture surface.
95
VIEW
ML00004 / Jun.2018
Creep in High Temperature Bolts
M - CrMo SteelP - FastenerAp - Gas TurbineCd - Creep
Cm - Nital Etched Micrography by OMDf - Crack
Micrographic detail of a longitudinal section of the bolt far from the fracture, presenting a tempered structure.
82
VIEW
ML00004 / Jun.2018
Creep in High Temperature Bolts
M - CrMo SteelP - FastenerAp - Gas TurbineCd - Creep
Cm - Nital Etched Micrography by OMDf - Tempered Structure
Micrographic detail of a longitudinal section of the bolt close to the fracture, presenting an overtempered structure.
76
VIEW
ML00004 / Jun.2018
Creep in High Temperature Bolts
M - CrMo SteelP - FastenerAp - Gas TurbineCd - Creep
Cm - Nital Etched Micrography by OMDf - Overtempered Structure