Theoretical work on the design of unusually high-strength steel weld deposits is compared with microstructural studies of an experimental, multipass submerged arc weld deposits. The as-deposited microstructure is found to consist of acicular ferrite, bainite and low-carbon martensite. Owing to its low carbon concentration, the structures is highly resistant to tempering, and because the alloy becomes austenitic at a relatively low temperature, the effect of reheating due to the deposition of several layers is found to be minimal. The overall microstructure of the multirun weld thus turns out to be fairly homogeneous, differing little from the as-deposited microstructure.
This scientific paper examines the microstructural evolution of high-strength, multi-run submerged arc-weld deposits. Through advanced microscopy and theoretical analysis, the researchers demonstrate that these welds are characterised by a complex multi-phase constituent profile. The study highlights how high hardenability and a low transformation temperature contribute to a remarkably homogeneous structure that remains stable even when subjected to the thermal cycles of subsequent welding passes.
Journal of Materials Science, Vol. 24, 1989, 3180-3188.
