Characterizing Phase Transformations in the Coarse-Grained Heat-Affected Zone of EH550 Offshore Engineering Steel Subjected to Varied High Heat Inputs
摘要
Solid-state phase transformations in the coarse-grained heat-affected zone subjected to varied heat input of EH550 grade steel are documented through in situ confocal scanning laser microscope. It is observed that, with the increment of heat input, dominating microstructure changes from bainite to a hybrid of bainite + ferrite side plate. Furthermore, slender bainites are found to transform into blocky ones, the growth rate of which decreases dramatically from 13.2 to 2.2 μm/s.