NItal Etched Macro

3 cases · 4 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Macrography of the transverse section of the tube, in a position where the cracking was not yet through wall. The internal tube surface shows multiple corrosion fatigue cracks, parallel, under the weld of the membrane, probably related to the cold side of the tube (the cracks opened to the boiler outside).   The external side of the tube presenting a small crack at the margem of the weld, suggesting also the action of thermal stresses.
214
ML00163 / Jun.2020
Corrosion Fatigue of a Boiler Waterwall Tube
M - Low Carbon SteelP - Seamless tubeAp - BoilerCd - Corrosion Fatigue
Cm - NItal Etched MacroDf - Multiple cracks
The macrography of a longitudinal section shows that the tube did not present local thinning in any region, but the internal and external scales are evidenced. The external surface (OD) is to the top of the figure and the internal surface (ID) is to the bottom of the figure.
123
ML00107 / Dec.2017
Carburized 9Cr1MoV Superheater Tube
M - Heat Resistant SteelP - Seamless tubeAp - BoilerCd - Carburization
Cm - NItal Etched MacroDf - Longitudinal Section
Macrography showing the different regions of a pipe-to-plate fillet weld. See the schematic drawing in the next image
954
ML00052 / Apr.2017
Cold Cracks in API 5CT L80 Tube Welded to a Structural Part
M - Low Alloy SteelP - Seamless tubeAp - OffshoreCd - Welding Defect
Cm - NItal Etched MacroDf - Fracture

More from these cases

ML00052 — Cold Cracks in API 5CT L80 Tube Welded to a Structural PartM - Low Alloy SteelP - Seamless tubeAp - OffshoreCd - Welding Defect
ML00052 / Apr.2017
Cold Cracks in API 5CT L80 Tube Welded to a Structural Part
M - Low Alloy SteelP - Seamless tubeAp - OffshoreCd - Welding Defect
Cm - NItal Etched MacroDf - Welded Joint