Literature survey and fracture analysis of deep and long cracks
in 3" to 12" thick steel weldments. Finite element
modeling study was completed in full penetration welds to study the sensitivity
of defects in the weld metal. The project lead to specific recommendations
to the preheat, interpass and post heat conditions to build tough welds.
Forensic analysis of photomicrographs indicated source and subsequent propagation
from hot crack formed during the early solidifcation stage
of the weld metal melt front. Acoustic stress waves were to cause the origin
of the initial defect of a hot crack.