Home » Boiler Tube Failure Handbook » Cracking » In or near weld or attachment Observation: Cracking » In or near weld or attachment 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 Brittle fracture in heat affected zone of a weld Cracking » In or near weld or attachment » Transverse or Random ReheaterSuperheater Graphitization Multiple cracks associated with attachment on outside of tube Cracking » In or near weld or attachment » Longitudinal or Random EconomizerWaterwall Corrosion Fatigue 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 Complete weld separation Cracking » In or near weld or attachment » Transverse Superheater Dissimilar Metal Weld Failure (DMW) Cracks close to attachments Cracking » In or near weld or attachment » Longitudinal Waterwall Corrosion Fatigue Appearance Observation Location Mechanism