| Appearance | Observation | Locations | Mechanism | |
|---|---|---|---|---|
|
Catastrophic failure associated with weld overlay | Cracking » In or near weld or attachment » Transverse | Waterwall | Hydrogen Damage |
|
Complete failure at weld | Cracking » In or near weld or attachment » Transverse | Superheater | Dissimilar Metal Weld CreepThermal Fatigue |
|
Transverse crack near support | Cracking » In or near weld or attachment » Transverse | Evaporator | Thermal Fatigue |
|
Complete weld separation | Cracking » In or near weld or attachment » Transverse | Superheater | Dissimilar Metal Weld Failure (DMW) |
| Appearance | Observation | Location | Mechanism |