Naked Eye or Stereoscope

3 cases · 11 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

Flat casting product presenting several thermal fatigue cracks all thorugh the surfaces. 1" thicknes.
171
ML00001 / Dec.2017
Thermal Fatigue of Cast Iron
M - Nodular Cast IronP - CastAp - SiderurgyCd - Thermal Fatigue
Cm - Transverse Section AspectDf - Cracks Transverse to the Surface
Macrography of the plate (thickness 22mm, in horizontal position) to tube (thickness 12.5 mm, in vertical position) welded joint. The half V groove was welded from the top (position inside the combustion chamber) in five weld beads, and with a small fillet welded from the water side (ouside of the tube). Average hardness of the plate is 180HV1 (1kg), of the tube is 150HV1 and of the weld is 190HV1. Maximum hardness of the tube HAZ is 165HV1 and plate HAZ is 195HV1.
219
ML00119 / Feb.2018
Thermal Fatigue of a Marine Boiler
M - Low Carbon SteelP - Fabrication WeldAp - ShipCd - Thermal Fatigue
Cm - NItal Etched MacroDf - Welded Joint
Aspect of the internal surface of the tube after longitudinal cut. 
This position is out of the damage area and only a small amount of deposits is evident.
216
ML00104 / Dec.2017
Thermal Fatigue of a Boiler Tube
M - Low Carbon SteelP - Autogenously Welded TubeAp - BoilerCd - Thermal Fatigue
Cm - Surface AspectDf - Internal Surface

More from these cases

ML00001 — Thermal Fatigue of Cast IronM - Nodular Cast IronP - CastAp - SiderurgyCd - Thermal Fatigue
Detail of figure 2, showing multiple fatigue cracks due to thermal cycles.
136
ML00001 / Dec.2017
Thermal Fatigue of Cast Iron
M - Nodular Cast IronP - CastAp - SiderurgyCd - Thermal Fatigue
Cm - NItal Etched MacroDf - Cracks Transverse to the Surface
ML00001 / Dec.2017
Thermal Fatigue of Cast Iron
M - Nodular Cast IronP - CastAp - SiderurgyCd - Thermal Fatigue
Cm - Transverse Section AspectDf - Acicular Alpha
ML00119 — Thermal Fatigue of a Marine BoilerM - Low Carbon SteelP - Fabrication WeldAp - ShipCd - Thermal Fatigue
ML00119 / Feb.2018
Thermal Fatigue of a Marine Boiler
M - Low Carbon SteelP - Fabrication WeldAp - ShipCd - Thermal Fatigue
Cm - Surface AspectDf - At the Surface
ML00119 / Feb.2018
Thermal Fatigue of a Marine Boiler
M - Low Carbon SteelP - Fabrication WeldAp - ShipCd - Thermal Fatigue
Cm - Surface AspectDf - Thermal Fatigue Cracks
ML00104 — Thermal Fatigue of a Boiler TubeM - Low Carbon SteelP - Autogenously Welded TubeAp - BoilerCd - Thermal Fatigue
Aspect of the internal surface of the tube after longitudinal cut. 
This position is at the damage area where a thick deposit is evident.
186
ML00104 / Dec.2017
Thermal Fatigue of a Boiler Tube
M - Low Carbon SteelP - Autogenously Welded TubeAp - BoilerCd - Thermal Fatigue
Cm - Surface AspectDf - Internal Surface
Aspect of the external surface of the tube, presenting a large circunferential crack.
171
ML00104 / Dec.2017
Thermal Fatigue of a Boiler Tube
M - Low Carbon SteelP - Autogenously Welded TubeAp - BoilerCd - Thermal Fatigue
Cm - Surface AspectDf - External Surface
Aspect of the internal surface of the tube after cleaning, presenting small circunferential cracks.
144
ML00104 / Dec.2017
Thermal Fatigue of a Boiler Tube
M - Low Carbon SteelP - Autogenously Welded TubeAp - BoilerCd - Thermal Fatigue
Cm - Surface AspectDf - Internal Surface
The macrography of a longitudinal section of the tube in the damaged area shows the circunferential cracks, from the internal and external sides of the tube. The outer diameter of the tube is in the top of the figure and the inner diameter is in the bottom of the figure.  From the outside there are several paralel cracks, as well as from the inner side.
126
ML00104 / Dec.2017
Thermal Fatigue of a Boiler Tube
M - Low Carbon SteelP - Autogenously Welded TubeAp - BoilerCd - Thermal Fatigue
Cm - NItal Etched MacroDf - Cracks