论文部分内容阅读
Characterization of the microstructure of the fusion boundary (FB) region of an Alloy 600-82 weld joint was conducted with focuses on the weld residual strain distribution and a comparison of the microstructure of heat affected zone (HAZ) with that of cold worked alloy.The HAZ in Alloy 600 has a lower fraction of CSL boundaries than that of the base alloy and a gradual increase of hardness was observed when approaching to the FB in HAZ.Peak of the residual strain was observed approached the FB in HAZ while the strain increased from the top of the weld to the root.Strain distribution in the HAZ was found to be concentrated adjacent to grain boundaries (GBs), with a peak of approximately three times of that in grain.Further, triple junctions of the GB appear to cause a higher strain concentration than single GBs.The microstructure of HAZ is partial tangled dislocations in comparison with slip bands in cold worked alloy consisting of high density dislocations.This may cause a relatively higher intergranular cracking resistance of HAZ due to the difference in behaviour of dislocation transfer to GB in HAZ and cold worked alloy under deformation.