Thermal Fatigue

3 cases · 3 images

Crevice Corrosion in a Subsea System — Aspect Before Analysis

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
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
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