|
External wastage beneath adherent slag deposit |
Deformation » Thinning
|
WaterwallSuperheater |
Corrosion From Slag Attack |
|
External thinning, smooth areas |
Deformation » Thinning
|
Reheater |
Fireside Corrosion/Erosion |
|
Smooth surface |
Deformation » Thinning
|
ReheaterSuperheater |
Fly Ash Erosion |
|
ID pitting with corrosion tubercles |
Holes, Pits, Gouges » Waterside
|
WaterwallReheaterSuperheater |
Oxygen Pitting |
|
sharply defined hole |
Holes, Pits, Gouges » Waterside
|
Economizer |
Corrosion Fatigue |
|
Undercut corrosion, multi-color deposits (red, white, black). (This is a view of a tube ID following cleaning.) |
Holes, Pits, Gouges » Waterside
|
Waterwall |
Acid Phosphate Attack |
|
Thinning on inside of a U-bend or other change in direction |
Holes, Pits, Gouges » Waterside
|
Economizer |
Flow Accelerated Corrosion (FAC) |
|
Defect at weld bar attachment |
Holes, Pits, Gouges » Fireside/Material Flaw
|
Waterwall |
Weld/Materials Defect |
|
Thinning from the fireside, pockmarks on external surface |
Holes, Pits, Gouges » Fireside
|
Waterwall |
Fireside Corrosion |
|
Catastrophic failure associated with weld overlay |
Cracking » In or near weld or attachment » Transverse
|
Waterwall |
Hydrogen Damage |
|
Circumferential cracking |
Cracking » Transverse » Not in or near a weld or attachment
|
Waterwall |
Thermal Fatigue |
|
Forming lap at tube OD |
Cracking » Longitudinal » Not in or near a weld
|
Waterwall |
Material Defect |
|
Fish-mouth rupture |
Cracking » Not in or near a weld
|
ReheaterSuperheater |
Short-Term Overheat |
|
Fish-mouth opening |
Cracking » Longitudinal » Not in or near a weld
|
Waterwall |
Hot Tensile Overload |
|
Thick-lipped rupture, may be very large window missing or a flap hanging by one edge |
Holes, Pits, Gouges
|
Waterwall |
Hydrogen Damage |
|
Short longitudinal cracks with numerous parallel cracks |
Cracking » Longitudinal » Not in or near a weld or attachment
|
ReheaterSuperheater |
Long-term Overheat/Creep |
|
Longitudinal crack at bend |
Cracking » Not in or near a weld or attachment
|
WaterwallReheaterSuperheater |
Long-term Overheat |
|
Complete failure at weld |
Cracking » In or near weld or attachment » Transverse
|
Superheater |
Thermal FatigueDissimilar Metal Weld Creep |
|
Brittle fracture in heat affected zone of a weld |
Cracking » In or near weld or attachment » Transverse or Random
|
ReheaterSuperheater |
Graphitization |
|
Longitudinal ID corrosion-fatigue cracks |
Cracking » In or near weld or attachment » Longitudinal
|
Waterwall |
Corrosion Fatigue |
|
Longitudinal cracks adjacent to weld |
Cracking » In or near weld or attachment » Longitudinal or Random
|
Superheater |
Wrong material/Creep |
|
Thick-lipped rupture and adjacent longitudinal fissuring |
Cracking » Longitudinal » Not Near Weld
|
ReheaterSuperheater |
Creep |
|
Complete weld separation |
Cracking » In or near weld or attachment » Transverse
|
Superheater |
Dissimilar Metal Weld Failure (DMW) |
|
Severe corrosion gouging at a weld-backing ring |
Holes, Pits, Gouges » Water/Steam Side
|
Waterwall |
Caustic Gouging |
|
Severe pock-marked corrosion on fireside |
Holes, Pits, Gouges
|
Furnace Riser |
Corrosion/Thermal Fatigue |
