Stress Corrosion

1 case · 13 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Transverse section of the fitting that suffered a longitudinal cracking. As polished. The wrought fitting has suffered intergranular stress corrosion cracking from the internal surface, exposed to hot caustic environment.
566
ML00011 / Oct.2017
Intergranular SCC of Pure Nickel
M - Unalloyed NickelP - Wrought FittingAp - Chemical IndustryCd - Stress Corrosion
Cm - Micrography by OMDf - Intergranular Cracking

More from these cases

ML00011 — Intergranular SCC of Pure NickelM - Unalloyed NickelP - Wrought FittingAp - Chemical IndustryCd - Stress Corrosion
The fitting presented through wall cracks that lead to leaking.  The internal aspect of the surface is presented where the cracks were still in the begining.
127
ML00011 / Oct.2017
Intergranular SCC of Pure Nickel
M - Unalloyed NickelP - Wrought FittingAp - Chemical IndustryCd - Stress Corrosion
Cm - Aspect Before AnalysisDf - Crack
Microstructure of the fitting in the transverse section, presenting a granular Ni austenitic structure.  No evidences of any phase in the grain boundaries.
113
ML00011 / Oct.2017
Intergranular SCC of Pure Nickel
M - Unalloyed NickelP - Wrought FittingAp - Chemical IndustryCd - Stress Corrosion
Cm - Kalling Etched Micrography by OMDf - Austenite
Microstructure of the fitting in the transverse section, presenting a granular Ni austenitic structure.  No evidences of any phase in the grain boundaries.
110
ML00011 / Oct.2017
Intergranular SCC of Pure Nickel
M - Unalloyed NickelP - Wrought FittingAp - Chemical IndustryCd - Stress Corrosion
Cm - Kalling Etched Micrography by OMDf - Austenite
ML00011 / Oct.2017
Intergranular SCC of Pure Nickel
M - Unalloyed NickelP - Wrought FittingAp - Chemical IndustryCd - Stress Corrosion
Cm - Kalling Etched Micrography by OMDf - Austenite
After opening the crack the fracture surface presented different aspects close to the internal surface and through the wall propagation.  Intergranular at the surface, showing intergranular SCC mechanism, and transgranular with striation, showing the contribution of pulsing loads.
101
ML00011 / Oct.2017
Intergranular SCC of Pure Nickel
M - Unalloyed NickelP - Wrought FittingAp - Chemical IndustryCd - Stress Corrosion
Cm - Fractography by SEMDf - Through Wall Cracking

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